Evidence for phosphorylation of pancreatic islet pyruvate kinase
MJ MacDonald, A Kowluru, CM Chang - Metabolism, 1985 - Elsevier
MJ MacDonald, A Kowluru, CM Chang
Metabolism, 1985•ElsevierRabbit pancreatic islet cytosol catalyzes the calcium-activated phosphorylation by [γ 32 P]
ATP of a protein with a molecular weight of 57,000 that is precipitated with antipyruvate
kinase antibodies. We were unable to demonstrate that phosphorylation in the presence of
calcium or cAMP had any immediate effect on rat pancreatic islet pyruvate kinase activity.
This finding is consistent with our inability to confirm the finding of others that pancreatic
islets contain phosphoenolpyruvate carboxykinase activity (Diabetes, 34: 246, 1985). Since …
ATP of a protein with a molecular weight of 57,000 that is precipitated with antipyruvate
kinase antibodies. We were unable to demonstrate that phosphorylation in the presence of
calcium or cAMP had any immediate effect on rat pancreatic islet pyruvate kinase activity.
This finding is consistent with our inability to confirm the finding of others that pancreatic
islets contain phosphoenolpyruvate carboxykinase activity (Diabetes, 34: 246, 1985). Since …
Abstract
Rabbit pancreatic islet cytosol catalyzes the calcium-activated phosphorylation by [γ32P]ATP of a protein with a molecular weight of 57,000 that is precipitated with antipyruvate kinase antibodies. We were unable to demonstrate that phosphorylation in the presence of calcium or cAMP had any immediate effect on rat pancreatic islet pyruvate kinase activity. This finding is consistent with our inability to confirm the finding of others that pancreatic islets contain phosphoenolpyruvate carboxykinase activity (Diabetes, 34:246, 1985). Since the carboxykinase catalyzes phosphoenolpyruvate formation and pyruvate kinase catalyzes essentially the opposite reaction, if the carboxykinase were present in the beta cell, pyruvate kinase would need to be inhibited to prevent recycling of phosphoenolpyruvate.
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