NMR structural studies of apolipoprotein E amino-terminal domain and amyloid beta peptide

Apolipoprotein E plays important roles in lipoprotein metabolism and transport. We have collected 3D/4D NMR data and completely assigned the backbone of the apoE amino terminal domain. Secondary structure analysis based on the assignment has shown similar four helical segments with the X-ray crystal structure. A flexible short alpha-helix in the carboxyl terminal region was found which extends beyond the four helices of the X-ray crystal structure. Domain-domain interaction doesn't have much impact on the structure of the amino terminal domain but strongly affect the structure of the carboxyl terminal domain.; Abeta peptide is the major culprit of the Alzheimer's Disease. We have established a high-level expression system for Abeta40. We also discovered a buffer system to control the starting conformation of Abeta peptide in vitro. Protein chemistry and spectroscopy technique were utilized to characterize the stability and structure transition of Abeta.