Structural and functional properties of V156K and A158E mutants of apolipoprotein A-I in the lipid-free and lipid-bound states
Structural and functional properties of V156K and A158E mutants of apolipoprotein A-I in the lipid-free and lipid-bound states
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DOI：
10.1194/jlr.m400468-jlr200
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发表时间：
2005-03-01
影响因子：
6.5
通讯作者：
Cho, KH
中科院分区：
文献类型：
--
作者：
Han, JM;Jeong, TS;Cho, KH
Val156 of apolipoprotein A-I (apoA-I) was found to be a key amino acid in the structure and function of high density lipoprotein (HDL) ( J. Biol. Chem., 275: 26821 - 26827, 2000). To determine more precisely the functions of the individual amino acids proximal to Val156, serial point mutants of proapoA- I, including V156K, D157K, and A158E, were overexpressed and purified to at least 95% purity. In the lipid-free state, A158E exhibited the most profound self-associative patterns and the least pronounced dimyristoyl phosphatidylcholine ( DMPC) clearance activities. In the lipid-bound state, A158E formed a larger reconstituted HDL (rHDL) with palmitoyloleoyl phosphatidylcholine ( POPC), similar to 120 Angstrom, whereas other mutants and the wild type (WT) formed 97 Angstrom of POPC-rHDL. Cross-linking analysis revealed that A158E-rHDL harbored at least four protein molecules in the particle, while other rHDL conformations contained only two protein molecules. All of the POPC-rHDL produced smaller HDL, around 78 Angstrom, after 24 h of incubation in the presence of low density lipoprotein at 37 degreesC. V156K and A158E exhibited decreased lecithin: cholesterol acyltransferase activation activity in the POPC-rHDL state, showing
