TY - JOUR
T1 - Regulation of fructose-6-phosphate 2-kinase by phosphorylation and dephosphorylation
T2 - Possible mechanism for coordinated control of glycolysis and glycogenolysis
AU - Furuya, E.
AU - Yokoyama, M.
AU - Uyeda, K.
PY - 1982
Y1 - 1982
N2 - The kinetic properties and the control mechanism of fructose-6-phosphate 2-kinase (ATP: D-fructose-6-phosphate 2-phosphotransferase) were investigated. The molecular weight of the enzyme is ≃ 100,000 as determined by gel filtration. The plot of initial velocity versus ATP concentration is hyperbolic with a K(m) of 1.2 mM. However, the plot of enzyme activity as a function of fructose 6-phosphate is sigmoidal. The apparent K(0.5) for fructose 6-phosphate is 20 μM. Fructose-6-phosphate 2-kinase is inactivated by the catalytic subunit of cyclic AMP-dependent protein kinase, and the inactivation is closely correlated with phosphorylation. The enzyme is also inactivated by phosphorylase kinase in the presence of Ca2+ and calmodulin. The phosphorylated fructose-6-phosphate 2-kinase, which is inactive, is activated by phosphorylase phosphatase and alkaline phosphatase. The possible physiological significance of these observations in the coordinated control of glycogen metabolism and glycolysis is discussed.
AB - The kinetic properties and the control mechanism of fructose-6-phosphate 2-kinase (ATP: D-fructose-6-phosphate 2-phosphotransferase) were investigated. The molecular weight of the enzyme is ≃ 100,000 as determined by gel filtration. The plot of initial velocity versus ATP concentration is hyperbolic with a K(m) of 1.2 mM. However, the plot of enzyme activity as a function of fructose 6-phosphate is sigmoidal. The apparent K(0.5) for fructose 6-phosphate is 20 μM. Fructose-6-phosphate 2-kinase is inactivated by the catalytic subunit of cyclic AMP-dependent protein kinase, and the inactivation is closely correlated with phosphorylation. The enzyme is also inactivated by phosphorylase kinase in the presence of Ca2+ and calmodulin. The phosphorylated fructose-6-phosphate 2-kinase, which is inactive, is activated by phosphorylase phosphatase and alkaline phosphatase. The possible physiological significance of these observations in the coordinated control of glycogen metabolism and glycolysis is discussed.
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U2 - 10.1073/pnas.79.2.325
DO - 10.1073/pnas.79.2.325
M3 - Article
C2 - 6281764
AN - SCOPUS:0345115927
SN - 0027-8424
VL - 79
SP - 325
EP - 329
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 2 I
ER -