Slow step in activation of muscle glycogen phosphorylase b by adenosine 5'-monophosphate.
The incubation of glycogen phosphorylase b from rabbit skeletal muscles with the allosteric activator (AMP) for 10-15 min has been found to result in an additional increase in the initial rate of the enzymatic reaction (v) as compared with the corresponding value of v measured by the initiation of the enzymatic reaction by the addition of a mixture of glucose 1-phosphate and AMP (0.02 M HEPES, pH 6.8; 37 degrees C). Glycogen with molecular mass of 270.10(6) daltons was used in the kinetic experiments. It is assumed that the enhancement of the rate of the phosphorylase b reaction is due to association of the enzyme molecules adsorbed to a glycogen particle resulting in an increase in the affinity of the enzyme for glycogen.
Kurganov
B I
BI
A. N. Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow.
Schors
E I
EI
Klinov
S V
SV
Chebotareva
N A
NA
D000249:Adenosine Monophosphate / Q000494:pharmacology*; D000494:Allosteric Regulation; D000818:Animals; D004789:Enzyme Activation; D005958:Glucosephosphates / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D007700:Kinetics; D008970:Molecular Weight; D018482:Muscle, Skeletal / Q000201:enzymology; D006005:Phosphorylases / Q000378:metabolism*; D011817:Rabbits
D005958:Glucosephosphates; D000249:Adenosine Monophosphate; D006003:Glycogen; C031590:glucose-1-phosphate; D006005:Phosphorylases