Document Detail

Adenylate kinase-catalyzed phosphoryl transfer couples ATP utilization with its generation by glycolysis in intact muscle.
MedLine Citation:
PMID:  7706272     Owner:  NLM     Status:  MEDLINE    
We previously suggested that an importance of adenylate kinase (AdK) in skeletal muscle is to function as a high energy phosphoryl transfer system regulating ATP generation in correspondence with its consumption by specific cellular processes. The present experiments are intended to define the ATP-generating system coupled to and regulated by AdK-catalyzed phosphotransfer in skeletal muscle and also to examine the relationship between AdK- and creatine kinase (CK)-catalyzed phosphotransfer. Rates of phosphoryl transfer catalyzed by AdK were assessed in intact, isolated rat diaphragm by determining rates of AMP phosphorylation with endogenously generated [gamma-18O]ATP under conditions of altered anaerobic and aerobic ATP production. AdK-catalyzed phosphoryl transfer rates accelerated incrementally up to 12-fold in direct proportion to stimulated contractile frequency in parallel with equivalent increases in rates of ATP generation by lactate producing glycolysis. Stoichiometric equivalent increases of AdK-catalyzed phosphotransfer and anaerobic ATP production also occurred up to more than 20-fold when oxidative phosphorylation was impaired by either O2 deprivation or treatment with KCN or p-(trifluoromethoxy)-phenylhydrazone. These enhanced rates of AMP phosphorylation were balanced by virtually identically increased rates of AdK-catalyzed generation of AMP. This AMP was traced to arise from AdK-catalyzed phosphotransfer involving ADP generated by a muscle ATPase. Increased AdK-catalyzed phosphotransfer paired with the apparent compensatory increase in ATP generation by anaerobic glycolysis in oxygen-deprived muscle occurred coincident with diminished rates of CK-catalyzed phosphoryl transfer indicative of a pairing between oxidatively produced ATP and CK-catalyzed phosphotransfer. A metabolic model consistent with these results and conforming to the Mitchell general principle of vectorial ligand conduction is suggested.
R J Zeleznikar; P P Dzeja; N D Goldberg
Publication Detail:
Type:  Comparative Study; In Vitro; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The Journal of biological chemistry     Volume:  270     ISSN:  0021-9258     ISO Abbreviation:  J. Biol. Chem.     Publication Date:  1995 Mar 
Date Detail:
Created Date:  1995-05-10     Completed Date:  1995-05-10     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  2985121R     Medline TA:  J Biol Chem     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  7311-9     Citation Subset:  IM    
Department of Biochemistry, University of Minnesota, Medical School, Minneapolis 55455, USA.
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MeSH Terms
Adenosine Diphosphate / metabolism
Adenosine Monophosphate / metabolism
Adenosine Triphosphate / metabolism*
Adenylate Kinase / metabolism*
Creatine Kinase / metabolism*
Diaphragm / metabolism
Lactates / analysis
Models, Biological
Muscle Contraction*
Muscle, Skeletal / metabolism*,  physiology
Oxygen Isotopes
Phosphotransferases / metabolism*
Rats, Sprague-Dawley
Grant Support
Reg. No./Substance:
0/Lactates; 0/Oxygen Isotopes; 56-65-5/Adenosine Triphosphate; 58-64-0/Adenosine Diphosphate; 61-19-8/Adenosine Monophosphate; EC 2.7.-/Phosphotransferases; EC Kinase; EC Kinase

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