DESCRIPTION: The aim of the proposed research is to develop newly designed membrane mimetics for NMR studies of the structure and dynamics of membrane associated proteins and peptides. These mimetics consist of detergent free mixtures of naturally occurring phospholipids with both neutral and anionic headgroups. The mixtures have a versatile phase diagram that includes an isotropic region as well as a magnetically ordered phase that can have either a positive or negative order parameter. In this proposal, the value of these mimetics will be demonstrated by carrying out high resolution and solid state NMR studies of representative membrane bound peptides and proteins chosen to illustrate the wide range of unsolved structural problems. Examples include, peptides from the myristoylated N-terminal segments of cAMP dependent protein kinase and a src tyrosine kinase, orphanin FQ (a neuropeptide), phospholipase A2, bombolin (a PLA2 activator) and the membrane spanning segment of glycophorin.