Synergistic effect of Ca2+ and Mg2+ upon the interaction of phosphorylase kinase with glycogen.
Phosphorylase kinase (ATP: phosphorylase-b phosphotransferase, EC 2.7.1.38) forms molecular complexes with glycogen over a range of conditions. The extent of interaction at pH 7.0, 20 degrees C, is greatly enhanced in the simultaneous presence of Ca2+ and Mg2+. If either cation is absent, the extent of complex formation is substantially reduced. Significant changes in the physical properties of phosphorylase kinase are observed in the presence of Ca2+ plus Mg2+, suggesting that a conformational change may occur under these conditions.
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D004357:Drug Synergism; D006003:Glycogen; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology*; D009132:Muscles / Q000201:enzymology*; D010764:Phosphorylase Kinase / Q000378:metabolism*; D011485:Protein Binding; D011817:Rabbits; D013053:Spectrophotometry
D006003:Glycogen; D010764:Phosphorylase Kinase; D008274:Magnesium; D002118:Calcium