Dephosphorylation and reactivation of phosphorylated purified ox-kidney branched-chain dehydrogenase complex by co-purified phosphatase

FEBS Lett. 1983 Jul 25;158(2):234-8. doi: 10.1016/0014-5793(83)80585-7.

Abstract

The branched-chain 2 oxoacid dehydrogenase complex has been purified from well-washed ox-kidney mitochondria together with branched-chain dehydrogenase kinase. The complex was inactivated and phosphorylated by ATP in about 5 min at 30 degrees C. After hydrolysis of ATP by a contaminating ATPase (5-10 min) the complex was dephosphorylated and reactivated. Dephosphorylation and reactivation were linearly correlated. Reactivation was dependent upon Mg2+ (K0.5 greater than 1 mM) and inhibited completely by 50 mM fluoride. Reactivation and dephosphorylation are attributed to a mitochondrial branched-chain dehydrogenase phosphatase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)
  • Animals
  • Calcium / pharmacology
  • Cattle
  • Enzyme Reactivators*
  • Fluorides / pharmacology
  • Ketone Oxidoreductases / antagonists & inhibitors
  • Ketone Oxidoreductases / metabolism*
  • Kidney / enzymology*
  • Magnesium / pharmacology
  • Male
  • Multienzyme Complexes / antagonists & inhibitors
  • Multienzyme Complexes / metabolism*
  • Phosphoric Monoester Hydrolases / pharmacology*
  • Phosphorylation

Substances

  • Enzyme Reactivators
  • Multienzyme Complexes
  • Ketone Oxidoreductases
  • 3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)
  • Phosphoric Monoester Hydrolases
  • Magnesium
  • Fluorides
  • Calcium