Maturation of high-density lipoproteins

Amy Y. Shih, Stephen G. Sligar, Klaus Schulten

Research output: Contribution to journalArticlepeer-review

Abstract

Human high-density lipoproteins (HDLs) are involved in the transport of cholesterol. The mechanism by which HDL assembles and functions is not well understood owing to a lack of structural information on circulating spherical HDL. Here, we report a series of molecular dynamics simulations that describe the maturation of discoidal HDL into spherical HDL upon incorporation of cholesterol ester as well as the resulting atomic level structure of a mature circulating spherical HDL particle. Sixty cholesterol ester molecules were added in a stepwise fashion to a discoidal HDL particle containing two apolipoproteins wrapped around a 160 dipalmitoylphosphatidylcholine lipid bilayer. The resulting matured particle, captured in a coarse-grained description, was then described in a consistent all-atom representation and analysed in chemical detail. The simulations show that maturation results from the formation of a highly dynamic hydrophobic core comprised of cholesterol ester surrounded by phospholipid and protein; the two apolipoprotein strands remain in a belt-like conformation as seen in the discoidal HDL particle, but with flexible N- and C-terminal helices and a central region stabilized by salt bridges. In the otherwise flexible lipoproteins, a less mobile central region provides an ideal location to bind lecithin cholesterol acyltransferase, the key enzyme that converts cholesterol to cholesterol ester during HDL maturation.

Original languageEnglish (US)
Pages (from-to)863-871
Number of pages9
JournalJournal of the Royal Society Interface
Volume6
Issue number39
DOIs
StatePublished - Oct 6 2009

Keywords

  • All-atom molecular dynamics
  • Apolipoprotein A-I
  • Coarse-grained modelling
  • High-density lipoprotein
  • Reverse coarse graining

ASJC Scopus subject areas

  • Biophysics
  • Biotechnology
  • Bioengineering
  • Biomedical Engineering
  • Biomaterials
  • Biochemistry

Fingerprint Dive into the research topics of 'Maturation of high-density lipoproteins'. Together they form a unique fingerprint.

Cite this