HDL has also been reported to remove and inactivate lipid hydroperoxides
from oxLDL upon co-incubation . These processes are
governed by the redox status of HDL-associated apolipoprotein AI
(apoAI), and the surface rigidity of the phospholipid monolayer of the acceptor HDL (as determined by the ratio of sphingomyelin/phosphatidylcholine). This ability to transfer oxidised lipids from oxLDL to
HDL may play an important part of the overall HDL anti-oxidative
capacity. However, the molecular details of the oxidised lipid transfer
capacity of HDL are not yet fully elucidated. Our knowledge on the identities
of the oxidised lipids that are actually transferred byHDL is limited
partly because studies have relied heavily on conjugated diene measurement
and HPLC chemiluminescence coupled with UV detection
measurement of lipid hydroperoxides. Here we aimed to oxidise lipoproteins
in an artificial system using copper chloride and to identify
major oxidised lipid species of oxLDL including oxPC, oxCE, and oxidised
cholesterols and investigate their transfer upon co-incubationwith HDL
with varying levels of oxidation.