Interaction of protein kinase C with phosphatidylserine. 1. Cooperativity in lipid binding

摘要: The basis for the apparent cooperativity in activation of protein kinase C by phosphatidylserine has been addressed using proteolytic sensitivity, resonance energy transfer, and enzymatic activity. We show that binding to detergent-lipid mixed micelles model membranes is cooperatively regulated phosphatidylserine. sigmoidal dependence on indistinguishable from observed this lipid [Newton & Koshland (1989) J. Biol. Chem. 264, 14909-14915]. Thus, activity linearly related amount bound. Furthermore, under conditions where bound at all concentrations, enzyme continues display a content micelle. This indicates does not arise because senses higher concentration once recruited Our results reveal affinity increases as more binds, supporting hypothesis domain sequestered around enzyme.