Resonance assignments and secondary structure of apolipoprotein E C-terminal domain in DHPC micelles.

Abstract

Human apolipoprotein E (apoE) has been known to play a key role in the transport of plasma cholesterol and lipoprotein metabolism. It is an apolipoprotein of 299 amino acids with a molecular mass, ~34kDa. ApoE has three major isoforms, apoE2, apoE3, and apoE4 which differ only at residue 112 or 158. ApoE consists of two independently folded domains (N-terminal and C-terminal domain) separated by a hinge region. The N-terminal domain and C-terminal domain of apoE are responsible for the binding to receptor and to lipid, respectively. Since the high resolution structures of apoE in lipids are still unavailable to date, we therefore aim to resolve the structures in lipids by NMR. Here, we reported the resonance assignments and secondary structure distribution of the C-terminal domain of wild-type human apoE (residue 195-299) in the micelles formed by dihexanoylphosphatidylcholine. Our results may provide a novel structural model of apoE in micelles and may shed new light on the molecular mechanisms underlying the apoE related biological processes.