Lecithin:cholesterol acyltransferase reduces the adverse effects of oxidized low-density lipoprotein while incurring damage itself.
In this study, we tried to determine (a) whether there is any permanent effect of oxLDL on the LCAT molecule and its activator lipoprotein apoA-I, and (b) the fate of oxLDL after its exposure to LCAT and apoA-I. Purified LCAT and LDL/oxLDL was incubated at 37 degrees C for 1 h, and separated by gel-permeation chromatography. Its activity was significantly less (30% less) after separating from oxLDL compared to that of LDL. Cofactor activity of isolated apoA-I (incubated with LDL/oxLDL) was found affected by oxLDL. These results indicate modification of the LCAT and apoA-I molecule. But LCAT was found more affected compared to apoA-I in terms of LCAT activity. We are also reporting a novel function of LCAT. It was found to reduce the adverse effects of oxLDL, for example, ability to affect the LCAT activity and TBARS value. This ability of LCAT to repair oxLDL was dose-dependent. But there was no change in its REM values or fluorescence intensity.
Howlader
Z H
ZH
Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.
Kamiyama
S
S
Murakami
Y
Y
Ito
M
M
Komai
M
M
Furukawa
Y
Y
D016632:Apolipoprotein A-I / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008077:Lipoproteins, LDL / Q000378:metabolism / Q000494:pharmacology*; D007862:Phosphatidylcholine-Sterol O-Acyltransferase / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D016632:Apolipoprotein A-I; D008077:Lipoproteins, LDL; D017392:Thiobarbituric Acid Reactive Substances; C099252:oxidized low density lipoprotein; D007862:Phosphatidylcholine-Sterol O-Acyltransferase