Regulation of AMP-deaminase activity from white muscle of common carp Cyprinus carpio.
AMP-deaminase was purified to electrophoretic homogeneity from white skeletal muscle of a teleost fish, the common carp, Cyprinus carpio. The purified enzyme was highly stable and showed non-Michaelis-Menten kinetics with a S(0.5) value for AMP of 2.52+/-0.16 mM (SEM) and a Hill coefficient of 1.19+/-0.11. Specific activity of the purified enzyme was 1000-1200 U/mg protein. The pH optimum was 6.3 and the enzyme was activated by ADP and ATP, but inhibited by phosphate and fluoride. Low concentrations of NaCl and KCl (100-150 mM) activated, whereas higher concentrations were inhibitory. Free radicals inactivated the enzyme, decreasing V(max) by one-half but not affecting S(0.5) or Hill coefficient. Possible regulatory mechanisms of AMP-deaminase activity in fish muscle are discussed.
Lushchak
Volodymyr I
VI
Department of Biochemistry, Precarpathian National University named after Vassyl Stefanyk, Ivano-Frankivsk, Ukraine. lushchak@pu.if.ua
Husak
Viktor V
VV
Storey
Kenneth B
KB
D000659:AMP Deaminase / Q000302:isolation & purification / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D000838:Anions / Q000494:pharmacology; D002347:Carps / Q000378:metabolism*; D002412:Cations / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000494:pharmacology; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology* / Q000378:metabolism; D014018:Tissue Distribution
D000838:Anions; D002412:Cations; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D006861:Hydrogen Peroxide; D007501:Iron; D000659:AMP Deaminase