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Chapter 3 Cooperative regulation of membrane enzymes by lipids

Publisher Summary This chapter discusses the cooperative regulation of membrane enzymes by lipids. It focuses on the studies of the functional aspects of lipid–protein interactions in the membrane. Multiple binding site models have been used to analyze the dependence of biochemical function on the concentrations of specific lipids. In these models, cooperative behavior can result either from energetic interactions among lipid binding sites or from the required solvation of the protein at multiple, independent sites. The latter case represents a functional extension of the boundary lipid concept originally proposed from electron spin resonance (ESR) spectroscopic studies of cytochrome oxidase–lipid interactions. In this model, in which the boundary layer lipid is dynamic rather than immobilized as originally proposed, the requirement for a full complement of solvating lipid can account, in some cases, for sigmoidal activation kinetics. However, this kind of non-cooperative binding of lipids at multiple solvation sites can account for only a limited range of cooperativity.