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).

All experiments were performed in compliance with institutional guidelines. Swine kidney was obtained fresh from the local supermarket. Liver tissues were harvested from C57BL6 wild-type mice maintained at the Institute for Biomedical Aging Research at Innsbruck University, Rennweg 10, 6020 Innsbruck, Austria under the supervision of Univ.-Doz. Dr. Pidder Jansen-D&#252;rr, covered by ethical permission as project leader issued in 2013 (BMWF-66.008/0007-II/3b/2013). Maintenance and use of the mice for the project are cove...

<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>

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 ...

Purification of recombinant protein from bacteria is a well-established method. However, several problems may occur when using these techniques. Having methods to extract protein from tissue is for sure appealing.The main advantage with this method is that one may extract the protein in its physiological form including all mutual effects that may impact its folding and catalytic activity. This approach may be adapted to other proteins of interest and modified for other tissue. Purified protein from tissue may support the development of high-quality antibodies and pharmacological inhibitors.To begin, prepare protein lysis buffer by mixing 250 milliliters of PBS with 50 millimolar sodium fluoride, one millimolar phenylmethylsulfonyl fluoride, two micrograms per milliliter aprotinin, and one millimolar activated orthovanadate. Filter the solution using a 0.22 micrometer syringe filter unit. Prepare tubes with two milliliters of lysis buffer per gram of tissue and place them on ice.To prepare the tissue sample, dissect the tissue of about 100 milligrams each on a pre-cleaned glass plate placed on ice in a polystyrene foam box. Transfer the tissue pieces into the prepared tubes for subsequent lysis. To prepare a saturated ammonium sulfate solution, heat 500 milliliters of double distilled water to 70 degrees Celsius.While stirring, gradually add ammonium sulfate powder until no more ammonium sulfate is dissolved. Cool this saturated solution to room temperature and store it at four degrees Celsius overnight. To homogenize the swine kidney tissues, sonicate the suspension preferably by an ultrasonic probe while keeping the sample on ice.In the case of mouse liver tissues, use an electric homogenizer and wash it regularly in PBS to prevent clogging while keeping the samples on ice. Take 20 microliters out of the samples and check under the microscope whether the cells of the homogenized tissue are properly destroyed. Otherwise, repeat the homogenization.Centrifuge the tubes at 10, 000 times G for 30 minutes at four degrees Celsius. Collect the supernatant in a fresh tube and place it on ice. Subsequently filter the supernatant using 0.45 micrometer and 0.22 micrometer syringe filter units.Aliquot the supernatant into 10 milliliter batches and freeze them at minus 20 degrees Celsius for short-term storage or at minus 80 degrees Celsius for longer storage. Prepare a 50 microliter sample for SDS-PAGE or Western blot analysis by adding 10 microliters of five times the SDS sample buffer to 40 microliters of the supernatant and then boiling at 95 degrees Celsius for 10 minutes. Prepare a discontinuous 12.5%polyacrylamide SDS-PAGE gel according to the manufacturer's instructions.To perform SDS-PAGE analysis, load the wells of the gel subsequently with a protein marker ladder, five nanograms of human FAHD1 recombinant protein as a positive control, 20 microliters of the sample to be analyzed, and the remaining wells with 20 microliters of prepared SDS-PAGE sample buffer. Run the SDS-PAGE gels at 125 volts using the SDS running buffer. After SDS-PAGE is complete, perform a Western blot analysis, probe the membranes using the available antibody raised against FAHD1.After preparing supernatant aliquots as described previously, either process after thawing or process directly after protein extraction without freezing the sample. Filter the sample using a 0.22 micrometer filter unit to exclude possible precipitates after thawing. Prepare six 1.5 milliliter tubes on ice, then transfer 250 microliters of sample into each tube.Prepare a dilution series of ammonium sulfate in the prepared tubes and make up the final volume to 1, 000 microliter with protein lysis buffer. Incubate the samples at four degrees Celsius overnight on a tube rotator. Using a tabletop centrifuge, centrifuge at 10, 000 times G for 30 minutes at four degrees Celsius and carefully transfer all of the supernatants into separate tubes.Air dry the resulting pellets and resuspend each of them in 1, 000 microliter of double distilled water. For each pair of resuspended pellet and supernatant from the previous step, mix 40 microliters with 10 microliters of five times the SDS sample buffer and boil at 95 degrees Celsius with open lids until most of the liquid has vaporized. Then resuspend the pellet in a mixture of 50%dimethyl sulfoxide in double distilled water.Perform SDS-PAGE by loading the samples derived from the resuspended pellets and supernatant in pairs, followed by a Western blot analysis. However, run the gels at 80 volts for three hours. Set up the FPLC system with the anionic or cationic exchange column.Wash the column with five column volumes of 20%ethanol in double distilled water, followed by five column volumes of double distilled water. Apply the sample onto the column either by injection or by using a sample pump and collect the flow-through. Wash the column with one column volume of the low salt buffer.Set up a linear gradient elution from 100%low salt buffer to 100%high salt buffer within three column volumes. Continuously collect one milliliter fractions. After the gradient has finished, continue to run with a high salt buffer until no more protein-associated peaks are detected in the chromatogram over the range of one column volume.Apply one milliliter of 25%SDS dissolved in 0.5 molar sodium hydroxide and double distilled water to clean the column. Consecutively wash the column with three column volumes of double distilled water and three column volumes of 20%ethanol in double distilled water. Collect the SDS-PAGE samples of all peak fractions and the flow-through.Snap freeze the collected fractions in liquid nitrogen and store them at minus 80 degrees Celsius. After probing them via Western blot, thaw and pool the fractions containing the proteins of interest and discard the others. To perform the purification step, reduce the volume of the protein solution down to two milliliters using ultra centrifugation filter units.Sequentially filter the solution with 0.45 micrometer and 0.22 micrometer syringe filter units to remove any microprecipitation. Equilibrate the size exclusion chromatography column with one column volume of running buffer containing one millimolar dithiothreitol. Load the sample onto the column and run the chromatography unit until all the proteins are eluted as described previously.Prepare 50 microliter samples for SDS-PAGE and Western blot analysis described previously. Consecutively wash the column with one column volume of double distilled water and one column volume of 20%ethanol in double distilled water. After performing Western blot analysis, pool all FAHD1 containing fractions.Reduce the volume of the protein solution down to two milliliters using ultra centrifugation filter units. Western blot screening shows the presence of swine FAHD1 in the supernatant with a band at 25 kilodaltons while the tagged positive control runs at 34 kilodaltons. The swine FAHD1 from lysate was purified by anionic exchange chromatography and the binding proteins were removed by elution.Fractions containing swine FAHD1 were identified by Western blot analysis, pooled and concentrated. Protein samples were purified by SEC and identified by Western blot analysis. The yield of swine FAHD1 protein was about one milligram with an 80%level of purity.Western blot analysis detected the mouse FAHD1 protein in the flow-through along with other proteins. The flow-through was applied for size exclusion chromatography. Fractions containing FAHD1 were pooled, concentrated, and applied to SDS-PAGE analysis.However, the yield of protein was not very high. The specific enzymatic activity of the swine FAHD1 increases with the purity level upon increasing the relative amount of FAHD1 per total protein. Higher concentrations of ammonium sulfate cause the smile effect, which can be resolved at lower voltage.Further protein was found in the lysate and supernatant at 15%concentration. However, at higher concentrations, samples may precipitate and cannot be detected. The protocol presented here requires that the protein is solvable.Optimal conditions for precipitation and pH or size adjustment for chromatography need to be tested and defined. The study of enzymatic function, the investigation of protein structure and the development of antibody are greatly supported when having protein extracted from tissue rather than extracted from bacteria.

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

Research

JoVE Journal

Biochemistry

4.4K vistas.  University of Innsbruck. La purificación de proteínas recombinantes de bacterias es un método bien establecido. Sin embargo, pueden ocurrir varios problemas al usar estas técnicas. Tener métodos para extraer proteínas de los tejidos es ciertamente atractivo.La principal ventaja de este método es que se puede extraer la proteína en su forma fisiológica, incluidos todos los efectos mutuos que pueden afectar su plegamiento y actividad catalítica. Este enfoque puede adaptarse a otras proteínas de inter?...