LIPID DYNAMICS AND PERIPHERAL INTERACTIONS OF PROTEINS WITH MEMBRANE SURFACES

A large body of evidence strongly indicates biomembranes to be organiz ed into compositionally and functionally specialized domains, supramol ecular assemblies, existing on different time and length scales. For t hese domains an intimate coupling between their chemical composition, physical state, organization, and functions has been postulated. One i mportant constituent of biomembranes are peripheral proteins whose act ivity can be controlled by non-covalent binding to lipids. Importantly , the physical chemistry of the lipid interface allows for a rapid and reversible control of peripheral interactions. In this review example s are provided on how membrane lipid (i) composition (i.e., specific l ipid structures), (ii) organization, and (iii) physical state can each regulate peripheral binding of proteins to the lipid surface, In addi tion, a novel and efficient mechanism for the control of the lipid sur face association of peripheral proteins by [Ca2+], lipid composition, and phase state is proposed. The phase state is, in turn, also depende nt on factors such as temperature, lateral packing, presence of ions, metabolites and drugs. Confining reactions to interfaces allows for fa cile and cooperative large scale integration and control of metabolic pathways due to mechanisms which are not possible in bulk systems.