The authors are very thankful for the technical assistance by Ayse &#214;zt&#252;rk and Eva Albertini. Mice used for the generation of liver tissue were maintained under the supervision of Univ.-Doz. Dr. Pidder Jansen-D&#252;rr (Institute for Biomedical Aging Research at Innsbruck University, Rennweg 10, 6020 Innsbruck, Austria).

<ol>
	<li>Pircher, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+FAH+domain-containing+protein+1+(FAHD1)+as+oxaloacetate+decarboxylase.">Identification of FAH domain-containing protein 1 (FAHD1) as oxaloacetate decarboxylase.</a> Journal of Biological Chemistry. 290 (11), 6755-6762 (2015).</li><li>Pircher, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+human+Fumarylacetoacetate+Hydrolase+Domain-containing+Protein+1+(FAHD1)+as+a+novel+mitochondrial+acylpyruvase.">Identification of human Fumarylacetoacetate Hydrolase Domain-containing Protein 1 (FAHD1) as a novel mitochondrial acylpyruvase.</a> Journal of Biological Chemistry. 286 (42), 36500-36508 (2011).</li><li>Kang, T. -. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Senescence+surveillance+of+pre-malignant+hepatocytes+limits+liver+cancer+development.">Senescence surveillance of pre-malignant hepatocytes limits liver cancer development.</a> Nature. 479 (7374), 547-551 (2011).</li><li>Hong, H., Seo, H., Park, W., Kim, K. K. -. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sequence,+structure+and+function-based+classification+of+the+broadly+conserved+FAH+superfamily+reveals+two+distinct+fumarylpyruvate+hydrolase+subfamilies.">Sequence, structure and function-based classification of the broadly conserved FAH superfamily reveals two distinct fumarylpyruvate hydrolase subfamilies.</a> Environmental Microbiology. 22 (1), 270-285 (2020).</li><li>Timm, D. E., Mueller, H. A., Bhanumoorthy, P., Harp, J. M., Bunick, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Crystal+structure+and+mechanism+of+a+carbon-carbon+bond+hydrolase.">Crystal structure and mechanism of a carbon-carbon bond hydrolase.</a> Structure. 7 (9), 1023-1033 (1999).</li><li>Bateman, R. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanistic+inferences+from+the+crystal+structure+of+Fumarylacetoacetate+Hydrolase+with+a+bound+phosphorus-based+inhibitor.">Mechanistic inferences from the crystal structure of Fumarylacetoacetate Hydrolase with a bound phosphorus-based inhibitor.</a> Journal of Biological Chemistry. 276 (18), 15284-15291 (2001).</li><li>Weiss, A. K. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+basis+for+the+bi-functionality+of+human+oxaloacetate+decarboxylase+FAHD1.">Structural basis for the bi-functionality of human oxaloacetate decarboxylase FAHD1.</a> Biochemical Journal. 475 (22), 3561-3576 (2018).</li><li>Etemad, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxaloacetate+decarboxylase+FAHD1+-+a+new+regulator+of+mitochondrial+function+and+senescence.">Oxaloacetate decarboxylase FAHD1 - a new regulator of mitochondrial function and senescence.</a> Mechanisms of Ageing and Development. 177, 22-29 (2019).</li><li>Weiss, A. K. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+cellular+senescence+by+eukaryotic+members+of+the+FAH+superfamily+-+A+role+in+calcium+homeostasis.">Regulation of cellular senescence by eukaryotic members of the FAH superfamily - A role in calcium homeostasis.</a> Mechanisms of Ageing and Development. 190, 111284 (2020).</li><li>Petit, M., Koziel, R., Etemad, S., Pircher, H., Jansen-D&#252;rr, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Depletion+of+oxaloacetate+decarboxylase+FAHD1+inhibits+mitochondrial+electron+transport+and+induces+cellular+senescence+in+human+endothelial+cells.">Depletion of oxaloacetate decarboxylase FAHD1 inhibits mitochondrial electron transport and induces cellular senescence in human endothelial cells.</a> Experimental Gerontology. 92, 7-12 (2017).</li><li>Wiley, C. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mitochondrial+dysfunction+induces+senescence+with+a+distinct+secretory+phenotype.">Mitochondrial dysfunction induces senescence with a distinct secretory phenotype.</a> Cell Metabolism. 23 (2), 303-314 (2016).</li><li>Weiss, A. K. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression,+purification,+crystallization,+and+enzyme+assays+of+Fumarylacetoacetate+Hydrolase+Domain-containing+proteins.">Expression, purification, crystallization, and enzyme assays of Fumarylacetoacetate Hydrolase Domain-containing proteins.</a> Journal of Visualized Experiments: JoVE. (148), e59729 (2019).</li><li>Weiss, A. K. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inhibitors+of+Fumarylacetoacetate+Hydrolase+Domain+Containing+Protein+1+(FAHD1).">Inhibitors of Fumarylacetoacetate Hydrolase Domain Containing Protein 1 (FAHD1).</a> Molcules. 26 (16), 5009 (2021).</li><li>Mizutani, H., Kunishima, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purification,+crystallization+and+preliminary+X-ray+analysis+of+the+fumarylacetoacetase+family+member+TTHA0809+from+Thermus+thermophilus+HB8.">Purification, crystallization and preliminary X-ray analysis of the fumarylacetoacetase family member TTHA0809 from Thermus thermophilus HB8.</a> Acta Crystallographica Section F Structural Biology and Crystallization Communications. 63 (9), 792-794 (2007).</li><li>Lee, C. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple+outline+of+methods+for+protein+isolation+and+purification.">A simple outline of methods for protein isolation and purification.</a> Endocrinology and Metabolism. 32 (1), 18-22 (2017).</li><li>Amer, H. E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purification+of+proteins:+Between+meaning+and+different+methods).">Purification of proteins: Between meaning and different methods).</a> Proteomics Technologies and Applications. , (2019).</li><li>Niu, L., Yuan, H., Gong, F., Wu, X., Wang, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protein+extraction+methods+shape+much+of+the+extracted+proteomes.">Protein extraction methods shape much of the extracted proteomes.</a> Frontiers in Plant Science. 9, 802 (2018).</li><li>Gordon, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+vanadate+as+protein-phosphotyrosine+phosphatase+inhibitor.">Use of vanadate as protein-phosphotyrosine phosphatase inhibitor.</a> Methods in Enzymology. 201, 477-482 (1991).</li><li>Gallagher, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SDS-polyacrylamide+gel+electrophoresis+(SDS-PAGE).">SDS-polyacrylamide gel electrophoresis (SDS-PAGE).</a> Current Protocols in Essential Laboratory Techniques. , (2012).</li><li>. Effect of pH on Protein Size Exclusion Chromatography Available from: <a target="_blank" href="https://www.agilent.com/cs/library/applications/5990-8138EN.pdf">https://www.agilent.com/cs/library/applications/5990-8138EN.pdf</a> (2011)</li><li>S&#248;rensen, B. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Silver+staining+of+proteins+on+electroblotting+membranes+and+intensification+of+silver+staining+of+proteins+separated+by+polyacrylamide+gel+electrophoresis.">Silver staining of proteins on electroblotting membranes and intensification of silver staining of proteins separated by polyacrylamide gel electrophoresis.</a> Analytical Biochemistry. 304 (1), 33-41 (2002).</li><li>Fagerberg, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+the+human+tissue-specific+expression+by+genome-wide+integration+of+transcriptomics+and+antibody-based+proteomics.">Analysis of the human tissue-specific expression by genome-wide integration of transcriptomics and antibody-based proteomics.</a> Molecular &amp; Cellular Proteomics. 13 (2), 397-406 (2014).</li><li>. Cytiva Life Fundamentals of size exclusion chromatography Available from: <a target="_blank" href="https://www.cytivalifesciences.com/en/us/solutions/protein-research/knowledge-center/protein-purification-methods/size-exclusion-chromatography">https://www.cytivalifesciences.com/en/us/solutions/protein-research/knowledge-center/protein-purification-methods/size-exclusion-chromatography</a> (2022)</li><li>Rosano, G. L., Ceccarelli, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recombinant+protein+expression+in+Escherichia+coli:+advances+and+challenges.">Recombinant protein expression in Escherichia coli: advances and challenges.</a> Frontiers in Microbiology. 5, 172 (2014).</li><li>Rosano, G. L., Morales, E. S., Ceccarelli, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+tools+for+recombinant+protein+production+in+Escherichia+coli:+A+5-year+update.">New tools for recombinant protein production in Escherichia coli: A 5-year update.</a> Protein Science: A Publication of the Protein Society. 28 (8), 1412-1422 (2019).</li></ol>

The authors have no competing financial interests.

Critical steps in the protocol 
Following common guidelines for the handling of proteins is essential, such as working on ice and at moderate pH and salt conditions. The use of protease inhibitors is beneficial to the method, while the use of proteasome inhibitors is highly recommended. Freezing and thawing the sample may always result in protein precipitation (at least partially), so any thawed aliquot of initial protein lysate (step 2) should be processed continuously without a break. Centrifugati...

The eukaryotic FAH domain-containing protein 1 (FAHD1) acts as bi-functional oxaloacetate (OAA) decarboxylase (ODx)1 and acylpyruvate hydrolase (ApH)2. It is localized in mitochondria2 and belongs to the broad FAH superfamily of enzymes1,2,3,4,5,6. While its ApH activity is only of minor relevance, the ODx activity of FAHD1 is involved in the regulation of the TCA cycle flux1,7,8,9. OAA is not only required for the central citrate synthase reaction in the tricarboxylic acid cycle but also acts as a competitive inhibitor of succinate dehydrogenase as part of the electron transport system and as a cataplerotic metabolite. Downregulation of FAHD1 gene expression in human umbilical vein endothelial cells (HUVEC) resulted in a significant reduction in the rate of cell proliferation10, and significant inhibition of mitochondrial membrane potential, associated with a concomitant switch to glycolysis. The working model refers to mitochondrial dysfunction associated senescence (MiDAS)11-like phenotype8, where mitochondrial OAA levels are tightly regulated by FAHD1 activity1,8,9.
Recombinant protein is easier to obtain via expression and purification from bacteria12 rather than from tissue. However, a protein expressed in bacteria may be biased by possible lack of post-translational modifications, or may simply be problematic (i.e., due to plasmid loss, bacterial stress responses, distorted/unformed disulfide bonds, none or poor secretion, protein aggregation, proteolytic cleavage, etc.). For certain applications, protein needs to be obtained from cell lysate or tissue, in order to include such modifications and/or to exclude possible artifacts. Purified protein from tissue supports the development of high-quality antibodies, and/or potent and specific pharmacological inhibitors for selected enzymes, such as for FAHD113.
This manuscript presents a series of methods for the extraction and purification of FAHD1 from swine kidney and mouse liver. The described methods require fast protein liquid chromatography (FPLC) but otherwise use common laboratory equipment. Alternative methods may be found elsewhere14,15,16,17. After total protein extraction, the proposed protocol involves a testing phase, in which sub-protocols for ammonium sulfate precipitation and ionic exchange chromatography are discussed (Figure 1). After defining these sub-protocols, the protein of interest is extracted via a sequential strategy using ionic exchange and size-exclusion chromatography with FPLC. Based on these guidelines, the final protocol may be adapted individually for other proteins of interest.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/63333/63333fig01.jpg" /> 
Figure 1: The overall strategy of this protocol. From top to bottom: Protein is extracted from tissues. Tissue homogenate is prepared, centrifuged, and filtrated. For each pair of supernatant and pellet-derived samples, tests for ammonium sulfate precipitation and ionic exchange chromatography (FPLC) need to be performed to probe for optimal conditions. After establishing these sub-protocols, the protein may be extracted via a sequential procedure of ammonium sulfate precipitation, ionic exchange chromatography, and repetitive size exclusion chromatography (FPLC) at varying pH and salt concentrations. All steps need to be controlled by western blot. <a href="https://www.jove.com/files/ftp_upload/63333/63333fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.22 &#181;m filter units</td>
			<td>MERCK</td>
			<td>SLGP033RS</td>
			<td>Millex-HP, 0.22 &#181;m, PES 33 mm, not steril</td>
		</tr>
		<tr>
			<td>0.45 &#181;m filter units</td>
			<td>MERCK</td>
			<td>SLHP033NS</td>
			<td>Millex-HP, 0.45 &#181;m, PES 33 mm, not steril</td>
		</tr>
		<tr>
			<td>15 mL Falcon tubes</td>
			<td>VWR</td>
			<td>734-0451</td>
			<td>centrifugal tubes</td>
		</tr>
		<tr>
			<td>50 mL Falcon tubes</td>
			<td>VWR</td>
			<td>734-0448</td>
			<td>centrifugal tubes</td>
		</tr>
		<tr>
			<td>96-Well UV Microplate</td>
			<td>Thermo-Fischer</td>
			<td>8404</td>
			<td>UV/VIS transparent flat-bottom 96 well plates</td>
		</tr>
		<tr>
			<td>Acrylamide/Bis Solution (40%, 29:1 ratio)</td>
			<td>BIO-RAD</td>
			<td>#1610147</td>
			<td>40% acrylamide/bis-acrylamide, 29:1 (3.3% crosslinker) solution for casting polyacrylamide gels</td>
		</tr>
		<tr>
			<td>&#196;KTA FPLC system</td>
			<td>GE Healthcare Life Sciences / Cytiva</td>
			<td>-</td>
			<td>using the FPLC system by GE Healthcare; different custom versions exist; this work used the &#34;&#196;KTA pure&#34; system</td>
		</tr>
		<tr>
			<td>Amicon Ultra-15, PLGC Ultracel-PL Membran, 10 kDa</td>
			<td>MERCK</td>
			<td>UFC901024</td>
			<td>centrifigal filters for protein enrichment; 10 kDa molecular mass filter; 15 mL</td>
		</tr>
		<tr>
			<td>Amicon Ultra-4, PLGC Ultracel-PL Membran, 10 kDa</td>
			<td>MERCK</td>
			<td>UFC801024</td>
			<td>centrifigal filters for protein enrichment; 10 kDa molecular mass filter; 4 mL</td>
		</tr>
		<tr>
			<td>Ammonium sulfate powder</td>
			<td>MERCK</td>
			<td>A4418</td>
			<td>ammonium sulphate for molecular biology, &#8805;99.0%</td>
		</tr>
		<tr>
			<td>Ammoniumpersulfat reagent grade, 98%</td>
			<td>MERCK</td>
			<td>215589</td>
			<td>Catalyst for acrylamide gel polymerization.</td>
		</tr>
		<tr>
			<td>Coomassie Brilliant blue R 250</td>
			<td>MERCK</td>
			<td>1125530025</td>
			<td>Coomassie Brilliant blue R 250 (C.I. 42660) for electrophoresis Trademark of Imperial Chemical Industries PLC. CAS 6104-59-2, pH 6.2 (10 g/l, H2O, 25 &#176;C)</td>
		</tr>
		<tr>
			<td>Dialysis tubing cellulose membrane</td>
			<td>MERCK</td>
			<td>D9277</td>
			<td>Cellulose membranes for the exchange of buffers via dialysis.</td>
		</tr>
		<tr>
			<td>Eppendof tubes 1.5 mL</td>
			<td>VWR</td>
			<td>525-1042</td>
			<td>microcentrifugal tubes; autoclaved</td>
		</tr>
		<tr>
			<td>HiLoad 26/600 Superdex 75 pg</td>
			<td>GE Healthcare Life Sciences / Cytiva</td>
			<td>28989334</td>
			<td>HiLoad Superdex 75 pg prepacked columns are for high-resolution size exclusion chromatography of recombinant proteins</td>
		</tr>
		<tr>
			<td>Immun-Blot PVDF Membrane</td>
			<td>BIO-RAD</td>
			<td>#1620177</td>
			<td>PVDF membranes are protein blotting membranes optimized for fluorescent and multiplex fluorescent applications.</td>
		</tr>
		<tr>
			<td>Mini Trans-Blot Electrophoretic Transfer Cell</td>
			<td>BIO-RAD</td>
			<td>#1703930</td>
			<td>Use the Mini Trans-Blot Cell for rapid blotting of Mini-PROTEAN precast and handcast gels.</td>
		</tr>
		<tr>
			<td>Mini-PROTEAN Tetra Vertical Electrophoresis Cell for Mini Precast Gels</td>
			<td>BIO-RAD</td>
			<td>#1658004</td>
			<td>4-gel vertical electrophoresis system, includes electrode assembly, companion running module, tank, lid with power cables, mini cell buffer dam.</td>
		</tr>
		<tr>
			<td>Mono Q 10/100 GL</td>
			<td>GE Healthcare Life Sciences / Cytiva</td>
			<td>17516701</td>
			<td>Mono Q columns are strong anion exchange chromatography columns for protein analysis or small scale, high resolution polishing of proteins.</td>
		</tr>
		<tr>
			<td>Mono S 10/100 GL</td>
			<td>GE Healthcare Life Sciences / Cytiva</td>
			<td>17516901</td>
			<td>Mono S columns are strong cation exchange chromatography columns for protein analysis or small scale high resolution polishing of proteins.</td>
		</tr>
		<tr>
			<td>PageRuler Prestained Protein Ladder, 10 to 180 kDa</td>
			<td>Thermo-Fischer</td>
			<td>26616</td>
			<td>A mixture of 10 blue-, orange-, and green-stained proteins (10 to 180 kDa) for use as size standards in protein electrophoresis (SDS-PAGE) and western blotting.</td>
		</tr>
		<tr>
			<td>Pierce BCA Protein Assay Kit</td>
			<td>Thermo-Fischer</td>
			<td>23225</td>
			<td>A two-component, high-precision, detergent-compatible protein assay for determination of protein concentration.</td>
		</tr>
		<tr>
			<td>Sonifier 250; Ultrasonic Cell Disruptor w/ Converter</td>
			<td>Branson</td>
			<td>-</td>
			<td>New models at https://www.emerson.com/documents/automation/brochure-sonifier-sfx250-sfx550-cell-disruptors-homogenizers-branson-en-us-168180.pdf</td>
		</tr>
		<tr>
			<td>Swine Anti-Rabbit Immunoglobulins/HRP (affinity isolated)</td>
			<td>Agilent Dako</td>
			<td>P0399</td>
			<td>The antibody used for horseradish peroxidase conjugation reacts with rabbit immunoglobulins of all classes.</td>
		</tr>
		<tr>
			<td>TEMED, 1,2-Bis(dimethylamino)ethane, TMEDA</td>
			<td>MERCK</td>
			<td>T9281</td>
			<td>TEMED (N,N,N&#8242;,N&#8242;-Tetramethylethylenediamine) is molecule which allows rapid polymerization of polyacrylamide gels.</td>
		</tr>
		<tr>
			<td>Tube Roller</td>
			<td>-</td>
			<td>-</td>
			<td>A general tube rotator roller; e.g. a new model at https://labstac.com/de/Mixer/Roller/c/71</td>
		</tr>
		<tr>
			<td>Tube Rotator</td>
			<td>-</td>
			<td>-</td>
			<td>A general tube rotator wheel; e.g. a new model at https://labstac.com/de/Tube-Roller/p/MT123</td>
		</tr>
		<tr>
			<td>ULTRA-TURRAX; T 25 digital</td>
			<td>IKA</td>
			<td>0003725000</td>
			<td>New models at https://www.ika.com/de/Produkte-Lab-Eq/Dispergierer-Dipergiergeraet-Homogenisierer-Homogenisator-csp-177/T-25-digital-ULTRA-TURRAX-cpdt-3725000/</td>
		</tr>
	</tbody>
</table>

extraction and purification of fahd1 protein from swine kidney and mouse liver

Fumarylacetoacetate hydrolase domain-containing protein 1 (FAHD1) is the first identified member of the FAH superfamily in eukaryotes, acting as oxaloacetate decarboxylase in mitochondria. This article presents a series of methods for the extraction and purification of FAHD1 from swine kidney and mouse liver. Covered methods are ionic exchange chromatography with fast protein liquid chromatography (FPLC), preparative and analytical gel filtration with FPLC, and proteomic approaches. After total protein extraction, ammonium sulfate precipitation and ionic exchange chromatography were explored, and FAHD1 was extracted via a sequential strategy using ionic exchange and size-exclusion chromatography. This representative approach may be adapted to other proteins of interest (expressed at significant levels) and modified for other tissues. Purified protein from tissue may support the development of high-quality antibodies, and/or potent and specific pharmacological inhibitors.

FAHD1 protein was extracted from swine kidney and mouse liver using the presented protocol. For mouse tissue, multiple organs are required to obtain several &#181;g after the final purification step. For this reason, this article focuses on the extraction of FAHD1 from swine kidneys, which is a much more exemplary experiment. The extraction of FAHD1 from the mouse liver is performed to present the difficulties and possible pitfalls of this protocol. It is generally recommended to use organs that show a high expression le...

Watch this Scientific Journal Video about Extraction and Purification of FAHD1 Protein from Swine Kidney and Mouse Liver at JoVE.com

Extraction and Purification of FAHD1 Protein from Swine Kidney and Mouse Liver

This protocol describes how to extract fumarylacetoacetate hydrolase domain-containing protein 1 (FAHD1) from swine kidney and mouse liver. The listed methods may be adapted to other proteins of interest and modified for other tissues.

Fumarylacetoacetate hydrolase domain-containing protein 1 (FAHD1) is the first identified member of the FAH superfamily in eukaryotes, acting as ...

extraction-purification-fahd1-protein-from-swine-kidney-mouse

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Biochemistry

4.6K Views.  University of Innsbruck. This protocol describes how to extract fumarylacetoacetate hydrolase domain-containing protein 1 (FAHD1) from swine kidney and mouse liver. The listed methods may be adapted to other proteins of interest and modified for other tissues.

Video: Extraction and Purification of FAHD1 Protein from Swine Kidney and Mouse Liver

Directed Protein Packaging within Outer Membrane Vesicles from Escherichia coli: Design, Production and Purification

An increasing interest in applying synthetic biology techniques to program outer membrane vesicles (OMV) are leading to some very interesting and unique applications for OMV where traditional nanoparticles are proving too difficult to synthesize. To date, all Gram-negative bacteria have been shown to produce OMV demonstrating packaging of a variety of cargo that includes small molecules, peptides, proteins and genetic material. Based on their diverse cargo, OMV are implicated in many biological processes ranging from cell-cell communication to gene transfer and delivery of virulence factors depending upon which bacteria are producing the OMV. Only recently have bacterial OMV become accessible for use across a wide range of applications through the development of techniques to control and direct packaging of recombinant proteins into OMV. This protocol describes a method for the production, purification, and use of enzyme packaged OMV providing for improved overall production of recombinant enzyme, increased vesiculation, and enhanced enzyme stability. Successful utilization of this protocol will result in the creation of a bacterial strain that simultaneously produces a recombinant protein and directs it for OMV encapsulation through creating a synthetic linkage between the recombinant protein and an outer membrane anchor protein. This protocol also details methods for isolating OMV from bacterial cultures as well as proper handling techniques and things to consider when adapting this protocol for use for other unique applications such as: pharmaceutical drug delivery, medical diagnostics, and environmental remediation.

Directed Protein Packaging within Outer Membrane Vesicles from Escherichia coli: Design, Production and Purification

A protocol for the production, purification, and use of enzyme packaged outer membrane vesicles (OMV) providing for enhanced enzyme stability for implementation across diverse applications is presented.

An increasing interest in applying synthetic biology techniques to program outer membrane vesicles (OMV) are leading to some very interesting and unique ...

Tandem Affinity Purification of Protein Complexes from Eukaryotic Cells

The purification of active protein-protein and protein-nucleic acid complexes is crucial for the characterization of enzymatic activities and de novo identification of novel subunits and post-translational modifications. Bacterial systems allow for the expression and purification of a wide variety of single polypeptides and protein complexes. However, this system does not enable the purification of protein subunits that contain post-translational modifications (e.g., phosphorylation and acetylation), and the identification of novel regulatory subunits that are only present/expressed in the eukaryotic system. Here, we provide a detailed description of a novel, robust, and efficient tandem affinity purification (TAP) method using STREP- and FLAG-tagged proteins that facilitates the purification of protein complexes with transiently or stably expressed epitope-tagged proteins from eukaryotic cells. This protocol can be applied to characterize protein complex functionality, to discover post-translational modifications on complex subunits, and to identify novel regulatory complex components by mass spectrometry. Notably, this TAP method can be applied to study protein complexes formed by eukaryotic or pathogenic (viral and bacterial) components, thus yielding a wide array of downstream experimental opportunities. We propose that researchers working with protein complexes could utilize this approach in many different ways.

We describe here a novel, robust, and efficient tandem affinity purification (TAP) method for the expression, isolation, and characterization of protein complexes from eukaryotic cells. This protocol could be utilized for the biochemical characterization of discrete complexes as well as the identification of novel interactors and post-translational modifications that regulate their function.

The purification of active protein-protein and protein-nucleic acid complexes is crucial for the characterization of enzymatic activities and de novo ...

Expression, Purification, and Antimicrobial Activity of S100A12

Calgranulin proteins are important mediators of innate immunity and are members of the S100 class of the EF-hand family of calcium binding proteins. Some S100 proteins have the capacity to bind transition metals with high affinity and effectively sequester them away from invading microbial pathogens in a process that is termed "nutritional immunity". S100A12 (EN-RAGE) binds both zinc and copper and is highly abundant in innate immune cells such as macrophages and neutrophils. We report a refined method for the expression, enrichment and purification of S100A12 in its active, metal-binding configuration. Utilization of this protein in bacterial growth and viability analyses reveals that S100A12 has antimicrobial activity against the bacterial pathogen, Helicobacter pylori. The antimicrobial activity is predicated on the zinc-binding activity of S100A12, which chelates nutrient zinc, thereby starving H. pylori which requires zinc for growth and proliferation.

Here, we present a method to express and purify S100A12 (calgranulin C). We describe a protocol to measure its antimicrobial activity against the human pathogen H. pylori.

Calgranulin proteins are important mediators of innate immunity and are members of the S100 class of the EF-hand family of calcium binding proteins. Some ...

Optimized Protocol for the Extraction of Proteins from the Human Mitral Valve

Analysis of the cellular proteome can help to elucidate the molecular mechanisms underlying diseases due to the development of technologies that permit the large-scale identification and quantification of the proteins present in complex biological systems.The knowledge gained from a proteomic approach can potentially lead to a better understanding of the pathogenic mechanisms underlying diseases, allowing for the identification of novel diagnostic and prognostic disease markers, and, hopefully, of therapeutic targets. However, the cardiac mitral valve represents a very challenging sample for proteomic analysis because of the low cellularity in proteoglycan and collagen-enriched extracellular matrix. This makes it challenging to extract proteins for a global proteomic analysis. This work describes a protocol that is compatible with subsequent protein analysis, such as quantitative proteomics and immunoblotting. This can allow for the correlation of data concerning protein expression with data on quantitative mRNA expression and non-quantitative immunohistochemical analysis. Indeed, these approaches, when performed together, will lead to a more comprehensive understanding of the molecular mechanisms underlying diseases, from mRNA to post-translational protein modification. Thus, this method can be relevant to researchers interested in the study of cardiac valve physiopathology.

The protein composition of the human mitral valve is still partially unknown, because its analysis is complicated by low cellularity and therefore by low protein biosynthesis. This work provides a protocol to efficiently extract protein for the analysis of the mitral valve proteome.

Analysis of the cellular proteome can help to elucidate the molecular mechanisms underlying diseases due to the development of technologies that permit ...

Purification of Hepatocytes and Sinusoidal Endothelial Cells from Mouse Liver Perfusion

This protocol demonstrates a method for obtaining high yield and viability for mouse hepatocytes and sinusoidal endothelial cells (SECs) suitable for culturing or for obtaining cell lysates. In this protocol, the portal vein is used as the site for catheterization, rather than the vena cava, as this limits contamination of other possible cell types in the final liver preparation. No special instrumentation is required throughout the procedure. A water bath is used as a source of heat to maintain the temperature of all the buffers and solutions. A standard peristaltic pump is used to drive the fluid, and a refrigerated table-top centrifuge is required for the centrifugation procedures. The only limitation of this technique is the placement of the catheter within the portal vein, which is challenging on some of the mice in the 18 - 25 g size range. An advantage of this technique is that only one vein is utilized for the perfusion and the access to the vein is quick, which minimizes ischemia and reperfusion of the liver that reduces hepatic cell viability. Another advantage to this protocol is that it is easy to distinguish live from dead hepatocytes by eyesight due to the difference in cellular density during the centrifugation steps. Cells from this protocol may be used in cell culture for any downstream application as well as processed for any biochemical assessment.

The goal of this protocol is to obtain high viability and high yield of hepatocytes and sinusoidal endothelial cells from liver. This is accomplished by perfusing the liver with a type IV collagenase solution via the portal vein, followed by differential centrifugation to obtain hepatocytes and sinusoidal endothelial cells.

This protocol demonstrates a method for obtaining high yield and viability for mouse hepatocytes and sinusoidal endothelial cells (SECs) suitable for ...

2 in 1: One-step Affinity Purification for the Parallel Analysis of Protein-Protein and Protein-Metabolite Complexes

Cellular processes are regulated by interactions between biological molecules such as proteins, metabolites, and nucleic acids. While the investigation of protein-protein interactions (PPI) is no novelty, experimental approaches aiming to characterize endogenous protein-metabolite interactions (PMI) constitute a rather recent development. Herein, we present a protocol that allows simultaneous characterization of the PPI and PMI of a protein of choice, referred to as bait. Our protocol was optimized for Arabidopsis cell cultures and combines affinity purification (AP) with mass spectrometry (MS)-based protein and metabolite detection. In short, transgenic Arabidopsis lines, expressing bait protein fused to an affinity tag, are first lysed to obtain a native cellular extract. Anti-tag antibodies are used to pull down protein and metabolite partners of the bait protein. The affinity-purified complexes are extracted using a one-step methyl tert-butyl ether (MTBE)/methanol/water method. Whilst metabolites separate into either the polar or the hydrophobic phase, proteins can be found in the pellet. Both metabolites and proteins are then analyzed by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS or UPLC-MS/MS). Empty-vector (EV) control lines are used to exclude false positives. The major advantage of our protocol is that it enables identification of protein and metabolite partners of a target protein in parallel in near-physiological conditions (cellular lysate). The presented method is straightforward, fast, and can be easily adapted to biological systems other than plant cell cultures.

Protein-protein and protein-metabolite interactions are crucial for all cellular functions. Herein, we describe a protocol that allows parallel analysis of these interactions with a protein of choice. Our protocol was optimized for plant cell cultures and combines affinity purification with mass spectrometry-based protein and metabolite detection.

Cellular processes are regulated by interactions between biological molecules such as proteins, metabolites, and nucleic acids. While the investigation of ...

Anaerobic Protein Purification and Kinetic Analysis via Oxygen Electrode for Studying DesB Dioxygenase Activity and Inhibition

Oxygen-sensitive proteins, including those enzymes which utilize oxygen as a substrate, can have reduced stability when purified using traditional aerobic purification methods. This manuscript illustrates the technical details involved in the anaerobic purification process, including the preparation of buffers and reagents, the methods for column chromatography in a glove box, and the desalting of the protein prior to kinetics. Also described are the methods for preparing and using an oxygen electrode to perform kinetic characterization of an oxygen-utilizing enzyme. These methods are illustrated using the dioxygenase enzyme DesB, a gallate dioxygenase from the bacterium Sphingobium sp. strain SYK-6.

Here we present a protocol for anaerobic protein purification, anaerobic protein concentration, and subsequent kinetic characterization using an oxygen electrode system. The method is illustrated using the enzyme DesB, a dioxygenase enzyme which is more stable and active when purified and stored in an anaerobic environment.

Oxygen-sensitive proteins, including those enzymes which utilize oxygen as a substrate, can have reduced stability when purified using traditional aerobic ...

Measuring and Interpreting Oxygen Consumption Rates in Whole Fly Head Segments

Regulated metabolic activity is essential for the normal functioning of living cells. Indeed, altered metabolic activity is causally linked with the progression of cancer, diabetes, neurodegeneration, and aging to name a few. For instance, changes in mitochondrial activity, the cell&#39;s metabolic powerhouse, have been characterized in many such diseases. Generally, the oxygen consumption rates of mitochondria were considered a reliable readout of mitochondrial activity and measurements in some of these studies were based on isolated mitochondria or cells. However, such conditions may not represent the complexity of a whole tissue. Recently, we have developed a novel method that enables the dynamic measurement of oxygen consumption rates from whole isolated fly heads. By utilizing this method, we have recorded lower oxygen consumption rates of the whole head segment in young versus aged flies. Secondly, we have discovered that lysine deacetylase inhibitors rapidly alter the oxygen consumption in the whole head. Our novel technique may therefore aid in uncovering new properties of various drugs, which may impact metabolic rates. Furthermore, our method may give a better understanding of metabolic behavior in an experimental setup that more closely resembles physiological states.

Measuring alterations in metabolic rates is central to understanding the progression of various diseases and aging. Here, we present a novel technique to measure whole head oxygen consumption that more closely resembles the physiological state and may aid in revealing novel drugs that modify mitochondrial activity.

Regulated metabolic activity is essential for the normal functioning of living cells. Indeed, altered metabolic activity is causally linked with the ...

Extraction and Analysis of Taiwanese Green Propolis

Taiwanese green propolis is rich in prenylated flavonoids and exhibits a broad range of biological activities, such as antioxidant, antibacterial, and anticancer ones. The bioactive compounds of Taiwanese green propolis are propolins, namely C, D, F, and G. The concentration of propolins in Taiwanese green propolis varies depending on the season and geographic location. Thus, it is critical to establish a standard and repeatable procedure for determining the quality of Taiwanese green propolis. Here, we present a protocol that uses ethanol-based extraction, high-performance liquid chromatography, and an antibacterial activity analysis to characterize Taiwanese green propolis quality. This method indicates that 95% and 99.5% ethanol extractions achieve the maximum dry matter yields from Taiwanese green propolis, thereby yielding the highest concentrations of propolins that have antibacterial properties. According to these findings, the present protocol is deemed reliable and repeatable for determining the quality of Taiwanese green propolis.

We present a protocol for using ethanol as a solvent to extract and characterize Taiwanese green propolis that exhibits antibacterial activity.

Taiwanese green propolis is rich in prenylated flavonoids and exhibits a broad range of biological activities, such as antioxidant, antibacterial, and ...

SUMO-Binding Entities (SUBEs) as Tools for the Enrichment, Isolation, Identification, and Characterization of the SUMO Proteome in Liver Cancer

Post-translational modification is a key mechanism regulating protein homeostasis and function in eukaryotic cells. Among all ubiquitin-like proteins in liver cancer, the modification by SUMO (Small Ubiquitin MOdifier) has been given the most attention. Isolation of endogenous SUMOylated proteins in vivo is challenging due to the presence of active SUMO-specific proteases. Initial studies of SUMOylation in vivo were based on the molecular detection of specific SUMOylated proteins (e.g., by western blot). However, in many cases, antibodies, generally made with non-modified recombinant protein, did not immunoprecipitate SUMOylated forms of the protein of interest.&#160;Nickel chromatography has been the other approach to study SUMOylation by capturing histidine-tagged versions of SUMO molecules. This approach is mainly used in cells stably expressing or transiently transfected with His-SUMO molecules. To overcome these limitations, SUMO-binding entities (SUBEs) were developed to isolate endogenous SUMOylated proteins. Herein, we describe all the steps required for the enrichment, isolation, and identification of SUMOylated substrates from human hepatoma cells and hepatic tissues from a liver cancer mouse model by using SUBEs. Firstly, we describe methods involved in the preparation and lysis of the human hepatoma cells and liver tumor tissue samples. Then, a thorough explanation of the preparation of SUBEs and controls is detailed along with the protocol for the protein pull-down assays. Finally, some examples are provided regarding the options available for the identification and characterization of the SUMOylated proteome, namely the use of western-blot analysis for the detection of a specific SUMOylated substrate from liver tumors or the use of proteomics by mass spectrometry for high-throughput characterization of the SUMOylated proteome and interactome in hepatoma cells.

SUMO-Binding Entities SUBEs as Tools for the Enrichment, Isolation, Identification, and Characterization of the SUMO Proteome in Liver Cancer

Here, we present a protocol to enrich, isolate, identify, and characterize proteins modified by SUMO in vivo both from human hepatoma cells and liver tumors obtained from mouse models of hepatocellular carcinoma by using SUMO-binding entities (SUBEs).

Post-translational modification is a key mechanism regulating protein homeostasis and function in eukaryotic cells. Among all ubiquitin-like proteins in ...