Rye K A, Jauhiainen M, Barter P J, Ehnholm C
Division of Cardiovascular Services, Royal Adelaide Hospital, South Australia.
J Lipid Res. 1998 Mar;39(3):613-22.
Phospholipid transfer protein (PLTP) converts high density lipoproteins (HDL) to larger and smaller particles during incubation in vitro. The present study shows that these conversions are enhanced in triglyceride (TG)-enriched HDL. When pig HDL were enriched with TG by incubation with cholesteryl ester transfer protein (CETP) and very low density lipoproteins, the TG/apoA-I molar ratio increased from 0.7/1 to 11.4/1 and the diameter increased from 9.0 to 9.5 nm. When unmodified pig HDL were incubated with PLTP, the diameter increased from 9.0 to 9.5 nm. Incubation of the TG-enriched pig HDL with PLTP generated larger (13.0 nm) and smaller (7.5 nm) particles. The composition of the large particles was comparable to the non-incubated, TG-enriched HDL. The small particles contained only phospholipids and apolipoprotein (apo) A-I. Studies were also carried out with spherical, reconstituted HDL (rHDL) containing only cholesteryl esters in their core. When the rHDL were enriched with TG by incubation with Intralipid and CETP, the diameter increased from 9.0 to 9.2 nm and the TG/apoA-I molar ratio became 5.7/1. When unmodified rHDL were incubated with PLTP, the diameter of 15% of the particles increased to 11.0 nm, 18% decreased to 7.6 nm, and 67% were unchanged. When the TG-enriched rHDL were incubated with PLTP, the diameter of 62% of the particles increased to 11.4 nm, 26% decreased to 7.6 nm, and 12% did not change. Preincubation with Intralipid alone or CETP alone did not enrich the rHDL with TG or enhance the size changes. These results show that the TG content of HDL has a major influence on PLTP-mediated size changes.
磷脂转运蛋白（PLTP）在体外孵育过程中可将高密度脂蛋白（HDL）转化为更大和更小的颗粒。本研究表明，在富含甘油三酯（TG）的HDL中，这些转化作用增强。当猪HDL与胆固醇酯转运蛋白（CETP）和极低密度脂蛋白一起孵育而富含TG时，TG/载脂蛋白A-I（apoA-I）摩尔比从0.7/1增加到11.4/1，直径从9.0 nm增加到9.5 nm。当未修饰的猪HDL与PLTP孵育时，直径从9.0 nm增加到9.5 nm。将富含TG的猪HDL与PLTP孵育可产生更大（13.0 nm）和更小（7.5 nm）的颗粒。大颗粒的组成与未孵育的、富含TG的HDL相当。小颗粒仅含有磷脂和载脂蛋白（apo）A-I。还对核心仅含胆固醇酯的球形重组HDL（rHDL）进行了研究。当rHDL与英脱利匹特和CETP一起孵育而富含TG时，直径从9.0 nm增加到9.2 nm，TG/apoA-I摩尔比变为5.7/1。当未修饰的rHDL与PLTP孵育时，15%的颗粒直径增加到11.0 nm，18%减小到7.6 nm，67%保持不变。当富含TG的rHDL与PLTP孵育时，62%的颗粒直径增加到11.4 nm，26%减小到7.6 nm，12%没有变化。单独用英脱利匹特或单独用CETP预孵育不会使rHDL富含TG或增强大小变化。这些结果表明，HDL的TG含量对PLTP介导的大小变化有重大影响。
