Lagrost L
Graduate School of Health and Medical Sciences, University of Wollongong, Australia.
Biochim Biophys Acta. 1992 Jun 22;1126(2):143-50. doi: 10.1016/0005-2760(92)90284-3.
The effect of the cholesteryl ester transfer protein (CETP) on the size redistribution of high density lipoprotein-3 (HDL3) particles containing either apolipoprotein A-I without apolipoprotein A-II, designated HDL3 (A-I w/o A-II), or apolipoprotein A-I with apolipoprotein A-II, designated HDL3 (A-I w A-II), was investigated by incubating HDL3 at 37 degrees C in the presence of a purified preparation of CETP. At the end of the incubation, the distribution of total HDL3 as well as HDL3 (A-I w/o A-II) particles, recovered after immunoprecipitation of HDL3 (A-I w A-II) particles with anti-apo A-II antibodies, was determined by non-denaturing polyacrylamide gradient gel electrophoresis. Total HDL3 ultracentrifugally isolated from plasma consisted of two distinct subpopulations of particles with apparent diameters of 8.5 and 7.8 nm. The distribution profile of HDL3 (A-I w/o A-II) particles, revealed that the HDL3 subpopulation with a mean diameter of 8.5 nm comprised two typs of particles, containing either only apo A-I or apo A-I with apo A-II, while the lipoprotein subpopulation with a mean diameter of 7.8 nm consisted exclusively of particles containing both apolipoproteins. During incubation at 37 degrees C, CETP induced the redistribution of HDL3 with a mean apparent diameter of 8.5 nm towards particle subpopulations of larger (9.4 nm diameter) and smaller (7.8 and 7.4 nm diameter) size. It was demonstrated that the CETP-mediated conversion of HDL3 concerned both type of particles. CETP preferentially induced the transformation of HDL3 (A-I w A-II) particles with a mean diameter of 8.5 nm into larger (9.4 nm diameter) and smaller (7.8 nm diameter) particles containing apo A-I and apo A-II. Secondly, CETP induced a shift of HDL3 (A-I w/o A-II) particles with a mean diameter of 8.5 nm towards particles of smaller size (7.4 nm diameter) containing only apo A-I, while HDL3 (A-I w A-II) particles with mean diameters of 7.8 and 9.4 nm remained stable. In addition, this study demonstrated that the redistribution of HDL3 particles was accompanied by a dissociation of apolipoprotein A-I from the lipoprotein surfaces. The effect of myristic acid on CETP-induced HDL3 redistribution was mainly due to a redistribution of HDL3 (AI w/o AII) particles.
通过在37℃下于纯化的胆固醇酯转运蛋白（CETP）制剂存在的条件下孵育高密度脂蛋白3（HDL3），研究了CETP对含有无载脂蛋白A-II的载脂蛋白A-I（称为HDL3（A-I w/o A-II））或含有载脂蛋白A-II的载脂蛋白A-I（称为HDL3（A-I w A-II））的HDL3颗粒大小重新分布的影响。孵育结束时，通过非变性聚丙烯酰胺梯度凝胶电泳测定总HDL3以及在用抗载脂蛋白A-II抗体免疫沉淀HDL3（A-I w A-II）颗粒后回收的HDL3（A-I w/o A-II）颗粒的分布。从血浆中超速离心分离得到的总HDL3由两个明显不同的颗粒亚群组成，其表观直径分别为8.5和7.8nm。HDL3（A-I w/o A-II）颗粒的分布图谱显示，平均直径为8.5nm的HDL3亚群包含两种颗粒类型，一种仅含有载脂蛋白A-I，另一种含有载脂蛋白A-I和载脂蛋白A-II，而平均直径为7.8nm的脂蛋白亚群仅由含有两种载脂蛋白的颗粒组成。在37℃孵育期间，CETP诱导平均表观直径为8.5nm的HDL3向更大（直径9.4nm）和更小（直径7.8和7.4nm）尺寸的颗粒亚群重新分布。结果表明，CETP介导的HDL3转化涉及两种颗粒类型。CETP优先诱导平均直径为8.5nm的HDL3（A-I w A-II）颗粒转化为含有载脂蛋白A-I和载脂蛋白A-II的更大（直径9.4nm）和更小（直径7.8nm）颗粒。其次，CETP诱导平均直径为8.5nm的HDL3（A-I w/o A-II）颗粒向仅含有载脂蛋白A-I的更小尺寸（直径7.4nm）颗粒转变，而平均直径为7.8和9.4nm的HDL3（A-I w A-II）颗粒保持稳定。此外，本研究表明HDL3颗粒的重新分布伴随着载脂蛋白A-I从脂蛋白表面解离。肉豆蔻酸对CETP诱导的HDL3重新分布的影响主要归因于HDL3（AI w/o AII）颗粒的重新分布。
