title: Thioredoxin fragment 31-36 is reduced by dihydrolipoamide and reduces oxidized protein.
abstract: The thioredoxin peptide Trp-Cys-Gly-Pro-Cys-Lys, which contains the redox active dithiol, was found to be reduced by lipoamide in a coupled reaction with lipoamide dehydrogenase and NADH. The reduced peptide in turn was shown to reduce insulin, oxidized lens protein and glyceraldehyde-3-phosphate dehydrogenase. While the peptide is not as effective a catalyst for utilizing pyridine nucleotides to reduce protein disulfides as thioredoxin, it offers a system which may be developed to provide more efficient disulfide reduction. This is particularly relevant since no thioredoxin peptides have been found to be active with thioredoxin reductase.
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D003459:Crystallins / Q000378:metabolism; D008058:Dihydrolipoamide Dehydrogenase / Q000378:metabolism; D004220:Disulfides / Q000378:metabolism; D004926:Escherichia coli / Q000032:analysis*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D007700:Kinetics; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D013053:Spectrophotometry; D008063:Thioctic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D013880:Thioredoxin-Disulfide Reductase / Q000378:metabolism; D013879:Thioredoxins / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D003459:Crystallins; D004220:Disulfides; D007328:Insulin; D010446:Peptide Fragments; D011506:Proteins; D009243:NAD; D013879:Thioredoxins; D008063:Thioctic Acid; C013091:lipoamide; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D008058:Dihydrolipoamide Dehydrogenase; D013880:Thioredoxin-Disulfide Reductase