title: A potent, heat-stable protein inhibitor of [branched-chain alpha-keto acid dehydrogenase]-phosphatase from bovine kidney mitochondria.
abstract: A heat- and acid-stable protein inhibitor of the [branched-chain alpha-keto acid dehydrogenase]-phosphatase was purified over 100,000-fold from extracts of bovine kidney mitochondria. The nearly homogeneous protein was recovered with a yield of 4-8%. The apparent molecular weight of the inhibitor is about 36,000. This protein is a noncompetitive inhibitor of the phosphatase, and the inhibitor constant (Ki) is about 0.13 nM. The inhibition was reversed 50% by about 1.3 mM Mg2+ and about 0.1 mM spermine. This protein inhibitor is different from the cytosolic protein phosphatase inhibitors 1 and 2.
authors.forename: Z
authors.initials: Z
authors.lastname: Damuni
authors.forename: J S
authors.initials: JS
authors.lastname: Humphreys
authors.forename: L J
authors.initials: LJ
authors.lastname: Reed
mesh_terms: D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide); D000597:Amino Acids, Branched-Chain / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D004791:Enzyme Inhibitors / Q000302:isolation & purification*; D006358:Hot Temperature; D007658:Ketone Oxidoreductases / Q000378:metabolism*; D007668:Kidney / Q000201:enzymology; D008274:Magnesium / Q000494:pharmacology; D008928:Mitochondria / Q000201:enzymology*; D008970:Molecular Weight; D009097:Multienzyme Complexes / Q000378:metabolism*; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases; D013096:Spermine / Q000494:pharmacology
chemical_list: D000597:Amino Acids, Branched-Chain; D004791:Enzyme Inhibitors; D009097:Multienzyme Complexes; D047428:Protein Kinase Inhibitors; D013096:Spermine; D007658:Ketone Oxidoreductases; D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide); D011494:Protein Kinases; C035627:(3-methyl-2-oxobutanoate dehydrogenase (lipoamide)) kinase; D008274:Magnesium