title: Proteomic analysis of carbonylated proteins in two-dimensional gel electrophoresis using avidin-fluorescein affinity staining.
abstract: A method for detecting carbonylated proteins in two-dimensional electrophoresis (2-DE) was developed using biotinylation and avidin-fluorescein isothiocyanate (FITC) affinity staining. The method was used to examine oxidatively modified proteins associated with oxidative stress. Carbonyl formation in proteins was first examined in a model system by subjecting bovine serum albumin (BSA) and ribonuclease A (RNase A) to metal-catalyzed oxidation (MCO). Carbonyl group formation was found to occur at multiple sites along with a small amount of polypeptide chain cleavage. In vivo studies were conducted in yeast cell cultures using 5 mM hydrogen peroxide to induce oxidative stress. Biotinylation of yeast protein was accomplished during extraction at 4 degrees C in a lysis buffer containing 5 mM biotin-hydrazide. Biotin-hydrazide forms a Schiff base with a carbonyl group on an oxidized protein that is subsequently reduced before electrophoresis. Proteins were separated by either 2-DE or sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Biotinylated species were detected using avidin-FITC affinity staining. Detection sensitivity with biotinylated proteins was five times higher than achieved by silver staining. The limit of detection with avidin-FITC staining approached 0.64 pmol of protein-associated carbonyls. Twenty carbonylated proteins were identified in the proteome of yeast following oxidative stress with hydrogen peroxide. Matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) analysis of tryptic peptides was used to identify peptides extracted from gels. Aconitase, heat shock protein SSA1 and SSC1, pyruvate decarboxylase isozyme 1, pyruvate kinase 1, enolase 1 and 2, phosphoglycerate kinase, fructose-bisphosphate aldorase, and glyceraldehyde-3-phosphate dehydrogenase were among the major targets of oxidative stress.
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, IN, USA.
authors.forename: Byoung-Sam
authors.initials: BS
authors.lastname: Yoo
authors.forename: Fred E
authors.initials: FE
authors.lastname: Regnier
mesh_terms: D000818:Animals; D001360:Avidin / Q000737:chemistry; D019921:Biotinylation; D002417:Cattle; D015180:Electrophoresis, Gel, Two-Dimensional; D019793:Fluorescein / Q000737:chemistry; D006861:Hydrogen Peroxide; D010084:Oxidation-Reduction; D012259:Ribonuclease, Pancreatic / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000737:chemistry; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013194:Staining and Labeling
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D001360:Avidin; D012710:Serum Albumin, Bovine; D006861:Hydrogen Peroxide; D012259:Ribonuclease, Pancreatic; D019793:Fluorescein