Apolipoprotein A-I helical structure and stability in discoidal high-density lipoprotein (HDL) particles by hydrogen exchange and mass spectrometry.

ABSTRACT: To understand high-density lipoprotein (HDL) structure at the molecular level, the location and stability of α-helical segments in human apolipoprotein (apo) A-I in large (9.6 nm) and small (7.8 nm) discoidal HDL particles were determined by hydrogen-deuterium exchange (HX) and mass spectrometry methods. The measured HX kinetics of some 100 apoA-I peptides specify, at close to amino acid resolution, the structural condition of segments throughout the protein sequence and changes in structure and stability that occur on incorporation into lipoprotein particles. When incorporated into the large HDL particle, the nonhelical regions in lipid-free apoA-I (residues 45-53, 66-69, 116-146, and 179-236) change conformation from random coil to α-helix so that nearly the entire apoA-I molecule adopts

SUBMITTER: Sevugan Chetty P 

PROVIDER: S-EPMC3406875 | biostudies-literature | 2012 Jul

REPOSITORIES: biostudies-literature