Name: optimized protocol for the extraction of proteins from the human mitral valve
Uploaded: 2017-06-14T14:00:00
Description: Watch this Scientific Journal Video about Optimized Protocol for the Extraction of Proteins from the Human Mitral Valve at JoVE.com

The Italian Ministry of Health supported this study (RC 2013-BIO 15). We thank Barbara Micheli for her excellent technical assistance.

In this protocol, the human hearts are collected during multiorgan explantation (cold ischemia time of 4-12 h, mean 6 &#177; 2 h) from multi-organ donors excluded from organ transplantation for technical or functional reasons, despite normal echocardiographic parameters. They are sent to the Cardiovascular Tissue Bank of Milan, Monzino Cardiologic Center (Milan, Italy) for the banking of the aortic and pulmonary valves. The mitral posterior leaflets are not used for clinical purposes, so they are collected during the aor...

<ol>
	<li>Vogel, C., Marcotte, E. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Insights+into+the+regulation+of+protein+abundance+from+proteomic+and+transcriptomic+analyses.">Insights into the regulation of protein abundance from proteomic and transcriptomic analyses.</a> Nat Rev Genet. 13 (4), 227-232 (2012).</li><li>de Sousa Abreu, R., Penalva, L. O., Marcotte, E. M., Vogel, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Global+signatures+of+protein+and+mRNA+expression+levels.">Global signatures of protein and mRNA expression levels.</a> Mol Biosyst. 5 (12), 1512-1526 (2009).</li><li>Hanash, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Disease+proteomics.">Disease proteomics.</a> Nature. 422 (6928), 226-232 (2003).</li><li>Ahram, M., Petricoin, E. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proteomics+Discovery+of+Disease+Biomarkers.">Proteomics Discovery of Disease Biomarkers.</a> Biomark Insights. 3, 325-333 (2008).</li><li>Chandramouli, K., Qian, P. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proteomics:+challenges,+techniques+and+possibilities+to+overcome+biological+sample+complexity.">Proteomics: challenges, techniques and possibilities to overcome biological sample complexity.</a> Hum Genomics Proteomics. 2009, (2009).</li><li>Singleton, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+advances+in+bioanalytical+sample+preparation+for+LC-MS+analysis.">Recent advances in bioanalytical sample preparation for LC-MS analysis.</a> Bioanalysis. 4 (9), 1123-1140 (2012).</li><li>Williams, T. H., Jew, J. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Is+the+mitral+valve+passive+flap+theory+overstated?+An+active+valve+is+hypothesized.">Is the mitral valve passive flap theory overstated? An active valve is hypothesized.</a> Med Hypotheses. 62 (4), 605-611 (2004).</li><li>Rabkin, E., 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=Activated+interstitial+myofibroblasts+express+catabolic+enzymes+and+mediate+matrix+remodeling+in+myxomatous+heart+valves.">Activated interstitial myofibroblasts express catabolic enzymes and mediate matrix remodeling in myxomatous heart valves.</a> Circulation. 104 (21), 2525-2532 (2001).</li><li>Martins Cde, O., 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=Distinct+mitral+valve+proteomic+profiles+in+rheumatic+heart+disease+and+myxomatous+degeneration.">Distinct mitral valve proteomic profiles in rheumatic heart disease and myxomatous degeneration.</a> Clin Med Insights Cardiol. 8, 79-86 (2014).</li><li>Tan, H. T., 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=Unravelling+the+proteome+of+degenerative+human+mitral+valves.">Unravelling the proteome of degenerative human mitral valves.</a> Proteomics. 15 (17), 2934-2944 (2015).</li><li>Banfi, C., 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=Proteome+of+platelets+in+patients+with+coronary+artery+disease.">Proteome of platelets in patients with coronary artery disease.</a> Exp Hematol. 38 (5), 341-350 (2010).</li><li>Banfi, C., 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=Proteomic+analysis+of+human+low-density+lipoprotein+reveals+the+presence+of+prenylcysteine+lyase,+a+hydrogen+peroxide-generating+enzyme.">Proteomic analysis of human low-density lipoprotein reveals the presence of prenylcysteine lyase, a hydrogen peroxide-generating enzyme.</a> Proteomics. 9 (5), 1344-1352 (2009).</li><li>Lowry, O. H., Rosebrough, N. J., Farr, A. L., Randall, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protein+measurement+with+the+Folin+phenol+reagent.">Protein measurement with the Folin phenol reagent.</a> J Biol Chem. 193 (1), 265-275 (1951).</li><li>Banfi, C., 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=Very+low+density+lipoprotein-mediated+signal+transduction+and+plasminogen+activator+inhibitor+type+1+in+cultured+HepG2+cells.">Very low density lipoprotein-mediated signal transduction and plasminogen activator inhibitor type 1 in cultured HepG2 cells.</a> Circ Res. 85 (2), 208-217 (1999).</li><li>Brioschi, M., 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=Normal+human+mitral+valve+proteome:+A+preliminary+investigation+by+gel-based+and+gel-free+proteomic+approaches.">Normal human mitral valve proteome: A preliminary investigation by gel-based and gel-free proteomic approaches.</a> Electrophoresis. 37 (20), 2633-2643 (2016).</li><li>Brioschi, M., Lento, S., Tremoli, E., Banfi, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Proteomic+analysis+of+endothelial+cell+secretome:+a+means+of+studying+the+pleiotropic+effects+of+Hmg-CoA+reductase+inhibitors.">Proteomic analysis of endothelial cell secretome: a means of studying the pleiotropic effects of Hmg-CoA reductase inhibitors.</a> J Proteomics. 78, 346-361 (2013).</li><li>Sun, S., Zhou, J. Y., Yang, W., Zhang, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inhibition+of+protein+carbamylation+in+urea+solution+using+ammonium-containing+buffers.">Inhibition of protein carbamylation in urea solution using ammonium-containing buffers.</a> Anal Biochem. 446, 76-81 (2014).</li><li>Rabilloud, T., Adessi, C., Giraudel, A., Lunardi, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improvement+of+the+solubilization+of+proteins+in+two-dimensional+electrophoresis+with+immobilized+pH+gradients.">Improvement of the solubilization of proteins in two-dimensional electrophoresis with immobilized pH gradients.</a> Electrophoresis. 18 (3-4), 307-316 (1997).</li><li>Santoni, V., Molloy, M., Rabilloud, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Membrane+proteins+and+proteomics:+un+amour+impossible?.">Membrane proteins and proteomics: un amour impossible?.</a> Electrophoresis. 21 (6), 1054-1070 (2000).</li><li>Shechter, D., Dormann, H. L., Allis, C. D., Hake, S. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extraction,+purification+and+analysis+of+histones.">Extraction, purification and analysis of histones.</a> Nat Protoc. 2 (6), 1445-1457 (2007).</li><li>Fujiki, Y., Hubbard, A. L., Fowler, S., Lazarow, P. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+intracellular+membranes+by+means+of+sodium+carbonate+treatment:+application+to+endoplasmic+reticulum.">Isolation of intracellular membranes by means of sodium carbonate treatment: application to endoplasmic reticulum.</a> J Cell Biol. 93 (1), 97-102 (1982).</li><li>Gorg, A., Weiss, W., Dunn, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+two-dimensional+electrophoresis+technology+for+proteomics.">Current two-dimensional electrophoresis technology for proteomics.</a> Proteomics. 4 (12), 3665-3685 (2004).</li><li>Mann, M., Kelleher, N. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Precision+proteomics:+the+case+for+high+resolution+and+high+mass+accuracy.">Precision proteomics: the case for high resolution and high mass accuracy.</a> Proc Natl Acad Sci U S A. 105 (47), 18132-18138 (2008).</li><li>Thakur, S. 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=Deep+and+highly+sensitive+proteome+coverage+by+LC-MS/MS+without+prefractionation.">Deep and highly sensitive proteome coverage by LC-MS/MS without prefractionation.</a> Mol Cell Proteomics. 10 (8), M110.003699 (2011).</li><li>Loardi, C., 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=Biology+of+mitral+valve+prolapse:+the+harvest+is+big,+but+the+workers+are+few.">Biology of mitral valve prolapse: the harvest is big, but the workers are few.</a> Int J Cardiol. 151 (2), 129-135 (2011).</li><li>Schoen, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolving+concepts+of+cardiac+valve+dynamics:+the+continuum+of+development,+functional+structure,+pathobiology,+and+tissue+engineering.">Evolving concepts of cardiac valve dynamics: the continuum of development, functional structure, pathobiology, and tissue engineering.</a> Circulation. 118 (18), 1864-1880 (2008).</li><li>Lelovas, P. P., Kostomitsopoulos, N. G., Xanthos, T. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparative+anatomic+and+physiologic+overview+of+the+porcine+heart.">A comparative anatomic and physiologic overview of the porcine heart.</a> J Am Assoc Lab Anim Sci. 53 (5), 432-438 (2014).</li></ol>

One critical step of this protocol is the use of liquid nitrogen to freeze the sample and to chill the grinder system. The use of liquid nitrogen prevents biological degradation and allows for efficient powdering, but it requires specific training for safe handling.
In this protocol features a grinder system for sample grinding because small samples are difficult to recover from standard mortar and pestles. In this case, small samples spread as a fine powder over the mortar surface, rendering ...

Recent evidence has altered the understanding of the roles of the many regulatory mechanisms that occur after mRNA synthesis. Indeed, translational, post-transcriptional, and proteolytic processes can regulate protein abundance and function. The dogma &#8211; which says that mRNA concentrations are proxies to those of the corresponding proteins, assuming that transcript levels are the main determinant of protein abundance &#8211; has been partially revised.Indeed, transcript levels only partially predict protein abundance, suggesting that post-transcriptional events occur to regulate the proteins within cells1,2.
Furthermore, proteins ultimately dictate the function of the cell and therefore dictate its phenotype, which can undergo dynamic changes in response to autocrine, paracrine, and endocrine factors; blood-borne mediators; temperature; drug treatment; and disease development. Thus, an expression analysis focused on the protein level is useful to characterize the proteome and to unravel the critical changes that occur to it as part of disease pathogenesis3.
Therefore, the opportunities that proteomics present to clarify health and disease conditions are formidable, despite the existing technological challenges. The particularly promising areas of research to which proteomics can contributeinclude: the identification of altered protein expression at any level (i.e., whole cells or tissue, subcellular compartments, and biological fluids); the identification, verification, and validation of novel biomarkers useful for the diagnosis and prognosis of disease; and, hopefully, the identification of new protein targets that can be used for therapeutic purposes, as well as for the assessment of drug efficacy and toxicity4.
Capturing the complexity of the proteome represents a technological challenge. The current proteomic tools offer the opportunity to perform large-scale, high-throughput analysis for the identification, quantification, and validation of altered protein levels. In addition, the introduction of fractionation and enrichment techniques, aimed at avoiding the interference caused by the most abundant proteins, has also improved protein identification by including the least abundant proteins. Finally, proteomics has been complemented by the analysis of post-translational modifications, which progressively emerge as important modulators of protein function.
However, the sample preparation and protein recovery in the biological specimens under analysis still remain the limiting steps in the proteomic workflow and increase the potential for possible pitfalls5. Indeed,in most of the molecular biology techniques that must be optimized, the first steps are tissue homogenization and cell lysis, especially during the analysis of low-abundance proteins for which amplification methods do not exist. In addition, the chemical nature of proteins can influence their own recovery. For example, the analysis of highly hydrophobic proteins is very challenging, because they easily precipitate during isoelectric focusing, while trans-membrane proteins are almost insoluble (reviewed in Reference 5). Furthermore, the tissue composition variability creates a significant barrier to developing a universal extraction method. Finally, because almost all of the clinical specimens are of limited quantity, it is essential to enable protein preparation with maximal recovery and reproducibility from minimal sample amounts6.
This work describes an optimized protocol for protein extraction from the normal human cardiac mitral valve, which represents a very challenging sample for proteomic analysis. The normal mitral valve is a complex structure lying between the left atrium and the left ventricle of the heart (Figure 1). It plays an important role in the control of blood flow from the atrium to the ventricle, preventing backflow and ensuring the proper level of oxygen supply to the whole body, thus maintaining an adequate cardiac output. However, it is often considered to be an &#34;inactive&#34; tissue, with a low cellularity and few components, mainly in the extracellular matrix. This is because, in normal conditions, the resident valvular interstitial cells (VICs) present a quiescent phenotype with a low protein biosynthesis rate7.
However, it has been demonstrated that, in a pathological state, the number of VICs in the spongiosa increases and their protein synthesis is activated, together with other functional and phenotypical changes8. Therefore, it is not surprising that the minimal data available in the literature focus on the analysis of pathological mitral valves9,10, in which the increased number of activated VICs might explain the relatively high number of identified proteins.
In conclusion, the present protocol may serve to develop the understanding of the pathogenic mechanisms responsible for mitral valve diseases through the study of mitral valve protein components. Indeed, a greater understanding of the underlying pathological processes could help to improve the clinical management of valve diseases, whose current indications for intervention are largely predicated on hemodynamic considerations.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Saline solution</td>
			<td></td>
			<td></td>
			<td>0.9 % NaCl</td>
		</tr>
		<tr>
			<td>Eurocollins A</td>
			<td>SALF</td>
			<td>30874046</td>
			<td>Balanced organ&#39;s transport medium. Combine 400 mL of Eurocollins A with 100 mL Eurocollins B to obtain balanced medium Eurocollins</td>
		</tr>
		<tr>
			<td>Eurocollins B</td>
			<td>SALF</td>
			<td>30874022</td>
			<td>Balanced organ&#39;s transport medium. Combine 400 mL of Eurocollins A with 100 mL Eurocollins B to obtain balanced medium Eurocollins</td>
		</tr>
		<tr>
			<td>Wisconsin</td>
			<td>Bridge life</td>
			<td>RM/N 4081</td>
			<td>Balanced organ&#39;s transport medium</td>
		</tr>
		<tr>
			<td>Biohazard vertical flow air</td>
			<td>Burdinola</td>
			<td></td>
			<td>Class A GMP classification</td>
		</tr>
		<tr>
			<td>Dewar Flask</td>
			<td>Thermo Scientific</td>
			<td>Nalgene 4150-1000</td>
			<td></td>
		</tr>
		<tr>
			<td>Cryogrinder system</td>
			<td>OPS diagnostics</td>
			<td>CG 08-01</td>
			<td>Grinder system containing mortars, pestles and screwdriver</td>
		</tr>
		<tr>
			<td>Stainless steel forceps</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Stainless steel spatula</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Disposable sterile scalpel</td>
			<td>Medisafe</td>
			<td>MS-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Stainless steel scissors</td>
			<td></td>
			<td></td>
			<td>Autoclavable</td>
		</tr>
		<tr>
			<td>Stainless steel picks</td>
			<td></td>
			<td></td>
			<td>Autoclavable</td>
		</tr>
		<tr>
			<td>Disposable sterile drap</td>
			<td>Mon&#38;Tex</td>
			<td>3.307.08</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterilizing solution with isopropyl alcohol</td>
			<td></td>
			<td></td>
			<td>70% isopropyl alcohol</td>
		</tr>
		<tr>
			<td>Sterilizing solution with hydrogen peroxide</td>
			<td></td>
			<td></td>
			<td>6% hydrogen peroxide</td>
		</tr>
		<tr>
			<td>Micropipette, 1 mL, with tips</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>15 mL centrifuge tubes</td>
			<td>VWR international</td>
			<td>9278</td>
			<td></td>
		</tr>
		<tr>
			<td>1.7 mL centrifuge tubes</td>
			<td>VWR international</td>
			<td>PIER90410</td>
			<td></td>
		</tr>
		<tr>
			<td>Urea buffer</td>
			<td></td>
			<td></td>
			<td>8 M urea, 2 M thiourea, 4 % w/v CHAPS, 20 mM Trizma, 55 mM Dithiotreitol</td>
		</tr>
		<tr>
			<td>Urea</td>
			<td>Sigma aldrich</td>
			<td>U6504-1KG</td>
			<td>To be used for Urea buffer</td>
		</tr>
		<tr>
			<td>Thiourea</td>
			<td>Sigma aldrich</td>
			<td>T8656</td>
			<td>To be used for Urea buffer</td>
		</tr>
		<tr>
			<td>CHAPS</td>
			<td>Sigma aldrich</td>
			<td>C3023-5GR</td>
			<td>To be used for Urea buffer</td>
		</tr>
		<tr>
			<td>Dithiotreitol</td>
			<td>Sigma aldrich</td>
			<td>D0632-5G</td>
			<td>To be used for Urea buffer</td>
		</tr>
		<tr>
			<td>Syringe 50 mL</td>
			<td>PIC</td>
			<td></td>
			<td>To be used to filter Urea buffer</td>
		</tr>
		<tr>
			<td>0.22 &#181;m filter</td>
			<td>Millipore</td>
			<td>SLGP033RB</td>
			<td>To be used to filter Urea buffer</td>
		</tr>
		<tr>
			<td>PFTE Pestle, 2 mL</td>
			<td>Kartell</td>
			<td>6302</td>
			<td>Part of Potter-Elvehjem homogenizer</td>
		</tr>
		<tr>
			<td>Borosilicate glass mortar</td>
			<td>Kartell</td>
			<td>6102</td>
			<td>Part of Potter-Elvehjem homogenizer</td>
		</tr>
		<tr>
			<td>Stirrer</td>
			<td>VELP scientifica</td>
			<td>Stirrer DLH</td>
			<td>To be used for homogenization by Potter-Elvehjem</td>
		</tr>
		<tr>
			<td>Bradford Protein assay</td>
			<td>Bio-Rad laboratories</td>
			<td>5000006</td>
			<td></td>
		</tr>
		<tr>
			<td>Tube rotator</td>
			<td>Pbi International</td>
			<td>F205</td>
			<td></td>
		</tr>
		<tr>
			<td>Liquid nitrogen</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Aluminum foil</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ice</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Polystyrene box</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Dry ice</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td></td>
			<td></td>
			<td>For centrifugation of 1.7 mL centrifuge tubes at 13,000 x g</td>
		</tr>
		<tr>
			<td>Freezer -80&#176;C</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Precision balance</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Autoclave</td>
			<td></td>
			<td></td>
			<td>For sterilization</td>
		</tr>
		<tr>
			<td>Cryogenic gloves for liquid nitrogen</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Gloves</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Professional forced ventilation and natural air convection oven</td>
			<td></td>
			<td></td>
			<td>For sterilization</td>
		</tr>
		<tr>
			<td>Protease inhibitor cocktail</td>
			<td>Sigma aldrich</td>
			<td>P8340-5ML</td>
			<td>100X solution</td>
		</tr>
		<tr>
			<td>ProteoExtract Protein Precipitation Kit</td>
			<td>Calbiochem</td>
			<td>539180</td>
			<td></td>
		</tr>
		<tr>
			<td>RapiGest</td>
			<td>Waters</td>
			<td>186001861</td>
			<td></td>
		</tr>
		<tr>
			<td>Cytoscape</td>
			<td>www.cytoscape.org</td>
			<td>version 2.7</td>
			<td>Software platform for Gene Ontology analysis</td>
		</tr>
		<tr>
			<td>BiNGO</td>
			<td>http://apps.cytoscape.org/apps/bingo</td>
			<td>version 3.0.3</td>
			<td>Plugin for Gene ontology analysis</td>
		</tr>
		<tr>
			<td>AlphaB Crystallin/CRYAB Antibody</td>
			<td>Novus Biologicals</td>
			<td>NBP1-97494</td>
			<td>Mouse monoclonal antibody against CryAB</td>
		</tr>
		<tr>
			<td>Septin-11 Antibody</td>
			<td>Novus Biologicals</td>
			<td>NBP1-83824</td>
			<td>Rabbit polyclonal antibody against septin-11</td>
		</tr>
		<tr>
			<td>FHL1 Antibody</td>
			<td>Novus Biologicals</td>
			<td>NBP-188745</td>
			<td>Rabbit polyclonal antibody against FHL-1</td>
		</tr>
		<tr>
			<td>Dermatopontin Antibody</td>
			<td>Novus Biologicals</td>
			<td>NB110-68135</td>
			<td>Rabbit polyclonal antibody against dermatopontin</td>
		</tr>
		<tr>
			<td>Goat Anti mouse IgG HRP</td>
			<td>Sigma aldrich</td>
			<td>A4416-0.5ML</td>
			<td>Secondary antibody for immunoblotting</td>
		</tr>
		<tr>
			<td>Goat Anti rabbit IgG HRP</td>
			<td>Bio-Rad laboratories</td>
			<td>170-5046</td>
			<td>Secondary antibody for immunoblotting</td>
		</tr>
	</tbody>
</table>

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 extraction and dissolution of proteins in the urea buffer is directly compatible with proteomic methods based on isoelectrofocusing (two-dimensional electrophoresis (2-DE)11 and liquid-phase isoelectric focusing (IEF)12) and with immunoblotting after dilution in Laemmli buffer13 containing a protease inhibitor cocktail14.
For gel-...

Watch this Scientific Journal Video about Optimized Protocol for the Extraction of Proteins from the Human Mitral Valve at JoVE.com

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

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 ...

Research

JoVE Journal

Biochemistry

An Optimized Protocol for Electrophoretic Mobility Shift Assay Using Infrared Fluorescent Dye-labeled Oligonucleotides

Electrophoretic Mobility Shift Assays (EMSA) are an instrumental tool to characterize the interactions between proteins and their target DNA sequences. ...

Purification of Biotinylated Cell Surface Proteins from Rhipicephalus microplus Epithelial Gut Cells

Purification of Biotinylated Cell Surface Proteins from Rhipicephalus microplus Epithelial Gut Cells

Rhipicephalus microplus &#8211; the cattle tick &#8211; is the most significant ectoparasite in terms of economic impact on livestock as a vector of ...

A Simple Fractionated Extraction Method for the Comprehensive Analysis of Metabolites, Lipids, and Proteins from a Single Sample

Understanding of complex biological systems requires the measurement, analysis and integration of multiple compound classes of the living cell, usually ...

Sampling and Pretreatment of Tooth Enamel Carbonate for Stable Carbon and Oxygen Isotope Analysis

Stable carbon and oxygen isotope analysis of human and animal tooth enamel carbonate has been applied in paleodietary, paleoecological, and ...

Covalent Immobilization of Proteins for the Single Molecule Force Spectroscopy

In recent years, atomic force microscopy (AFM) based single molecule force spectroscopy (SMFS) extended our understanding of molecular properties and ...

Characterization of Proteins by Size-Exclusion Chromatography Coupled to Multi-Angle Light Scattering (SEC-MALS)

Characterization of Proteins by Size-Exclusion Chromatography Coupled to Multi-Angle Light Scattering SEC-MALS

Analytical size-exclusion chromatography (SEC), commonly used for the determination of the molecular weight of proteins and protein-protein complexes in ...

Transverse Sectioning of Mature Rice (Oryza sativa L.) Kernels for Scanning Electron Microscopy Imaging Using Pipette Tips as Immobilization Support

Transverse Sectioning of Mature Rice Oryza sativa L. Kernels for Scanning Electron Microscopy Imaging Using Pipette Tips as Immobilization Support

Starch granules (SGs) exhibit different morphologies depending on the plant species, especially in the endosperm of the Poaceae family. Endosperm ...

Optimized Incorporation of Alkynyl Fatty Acid Analogs for the Detection of Fatty Acylated Proteins using Click Chemistry

Fatty acylation, the covalent addition of saturated fatty acids to protein substrates, is important in regulating a myriad of cellular functions in ...

Paramagnetic Relaxation Enhancement for Detecting and Characterizing Self-Associations of Intrinsically Disordered Proteins

Intrinsically disordered proteins and intrinsically disordered regions within proteins make up a large and functionally significant part of the human ...

Ultrasonic-Assisted Extraction of Cannabidiolic Acid from Cannabis Biomass

Ultrasonic-Assisted Extraction of Cannabidiolic Acid from Cannabis Biomass

Industrial hemp (Cannabis spp.) has many compounds of interest with potential medical benefits. Of these compounds, cannabinoids have come to the center ...