title: Multi-site phosphorylation in ox-kidney branched-chain 2-oxoacid dehydrogenase complex.
abstract: Tryptic [32P]phosphopeptides were prepared from [32P]phosphorylated ox-kidney branched-chain complex and analysed by high-voltage paper electrophoresis at pH 1.9. In the maximally phosphorylated complex 3 tryptic [32P]phosphopeptides were identified (TA, TB, TC). RF-values relative to N6-dinitrophenyllysine were (mean +/- SEM for 25 obs.): TA, 1.53 +/- 0.03; TB, 1.07 +/- 0.02; TC, 0.65 +/- 0.01. Relative rates of phosphorylation were TA greater than TB greater than TC. Phosphorylation of TA reached a maximum when about 66% of the complex was inactivated. Phosphorylation of TB and TC was associated mainly with 66-95% inactivation of the complex.
mesh_terms: D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide); D000818:Animals; D002417:Cattle; D007658:Ketone Oxidoreductases / Q000378:metabolism*; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D009097:Multienzyme Complexes / Q000378:metabolism*; D010446:Peptide Fragments / Q000032:analysis; D010748:Phosphopeptides / Q000032:analysis; D010761:Phosphorus Radioisotopes; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D014357:Trypsin
chemical_list: D009097:Multienzyme Complexes; D010446:Peptide Fragments; D010748:Phosphopeptides; D010761:Phosphorus Radioisotopes; D007658:Ketone Oxidoreductases; D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide); D011494:Protein Kinases; C035627:(3-methyl-2-oxobutanoate dehydrogenase (lipoamide)) kinase; D014357:Trypsin