Effects of acyl chain length, unsaturation, and pH on thermal stability of model discoidal HDLs.

ABSTRACT: HDLs prevent atherosclerosis by removing excess cell cholesterol. Lipid composition affects HDL functions in cholesterol removal, yet its effects on the disk stability remain unclear. We hypothesize that reduced length or increased cis-unsaturation of phosphatidylcholine acyl chains destabilize discoidal HDL and promote protein dissociation and lipoprotein fusion. To test this hypothesis, we determined thermal stability of binary complexes reconstituted from apoC-I and diacyl PCs containing 12-18 carbons with 0-2 cis-double bonds. Kinetic analysis using circular dichroism shows that, for fully saturated PCs, chain length increase by two carbons stabilizes lipoprotein by deltaDeltaG* (37 degrees C) congruent with 1.4 kcal/mol, suggesting that hydrophobic interactions dominate the disk stabi

SUBMITTER: Guha M 

PROVIDER: S-EPMC2444001 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature