Apolipoprotein E: phospholipid binding studies with synthetic peptides containing the putative receptor binding region. Academic Article uri icon

Overview

abstract

  • To define the lipid and receptor binding regions of apolipoprotein E (apoE), we have synthesized four peptides beginning at residue 169 and continuing through the putative receptor binding region and ending at residue 129 so as to include a proposed lipid binding domain. The peptides were synthesized by solid-phase techniques, cleaved with anhydrous HF, and purified by ion-exchange and semipreparative reversed-phase high-performance liquid chromatography (HPLC). The peptides had the correct amino acid composition and were greater than 99% pure by analytical reversed-phase HPLC. The circular dichroic spectrum of each peptide was recorded before and after mixing with dimyristoylphosphatidylcholine. With apoE (148-169), apoE (144-169), and apoE (139-169), no changes were observed in the ellipticity at 222 nm. However, with apoE (129-169), an increase in alpha-helicity to approximately 42% was observed. Density gradient ultracentrifugation of the lipid-peptide mixture permitted isolation of a complex with apoE (129-169) with a molar ratio of lipid to peptide of 125:1, which was stable to recentrifugation. The alpha-helicity of the peptide in the complex was estimated to be 56%. No complexes were isolated from the gradients of the shorter peptides. Therefore, we conclude that the amphipathic helix formed by residues 130-150 contains one of the lipid binding regions of apoE.

publication date

  • November 19, 1985

Research

keywords

  • Apolipoproteins E
  • Dimyristoylphosphatidylcholine
  • Receptors, Cell Surface

Identity

Scopus Document Identifier

  • 0022371632

Digital Object Identifier (DOI)

  • 10.1021/bi00345a035

PubMed ID

  • 3000443

Additional Document Info

volume

  • 24

issue

  • 24