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标题：Effect of acylglyceride content on the structure and function of reconstituted high density lipoprotein particles
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作者：Sylvie Braschi ; Cynthia R. Coffill ; Tracey A-M. Neville 等
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：2001
卷号：42
期号：1
页码：79-87
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：The effects of different acylglycerides on the conformation and charge of apolipoprotein A-I (apoA-I) have been investigated in reconstituted high density lipoproteins (LpA-I). Various amounts of diacylglycerol (DG) and triacylglycerol (TG) were incorporated into sonicated spherical LpA-I particles containing 2 molecules of apoA-I and 80 molecules of phospholipid. Inclusion of 30 molecules of TG into the LpA-I particle increases the net negative charge of apoA-I (−8.5 to −9.3 mV), but has little effect on the amount and thermodynamic stability of the α helices in apoA-I. Incorporation of 30 molecules of DG into the lipoprotein complex promotes a small increase in the α-helix content and stability, but greatly increases the net negative charge of apoA-I (−8.5 to −11.2 mV). Inclusion of DG increases the immunoreactivity of two epitopes in the N terminus of apoA-I, but decreases the exposure of a domain closer to the C terminus (residues 148–186) of the apoprotein. In contrast, TG increases the exposure of epitopes over the entire apoA-I molecule; TG increases the immunoreactivity of epitopes for 13 different monoclonal antibodies to apoA-I. Incubations with purified lecithin:cholesterol acyltransferase show that cholesterol esterification is stimulated by DG, but inhibited by TG. The data show that TG and DG have different effects on apoA-I structure and function and this suggests that the TG-to-DG ratio in HDL may directly affect the metabolism of this lipoprotein class. —Braschi, S., C. R. Coffill, T. A-M. Neville, D. M. Hutt, and D. L. Sparks. Effect of acylglyceride content on the structure and function of reconstituted high density lipoprotein particles. J. Lipid Res. 2001. 42: 79–87.
关键词：HDL ; apolipoprotein A-I ; diglyceride ; triglyceride ; charge ; stability ; conformation ; immunochemistry ; LCAT