Department of Chemistry, Graduate School of Science , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan.
JST ERATO, Lipid Active Structure Project , Osaka University , 1-1 Machikaneyama , Toyonaka , Osaka 560-0043 , Japan.
Biochemistry. 2019 Sep 17;58(37):3869-3879. doi: 10.1021/acs.biochem.9b00469. Epub 2019 Sep 4.
The average conformation of the methyl-branched chains of archaeal lipid phosphatidyl glycerophosphate methyl ester (PGP-Me) was examined in a hydrated bilayer membrane based on the H nuclear magnetic resonance (NMR) of enantioselectively H-labeled compounds that were totally synthesized for the first time in this study. The NMR results in combination with molecular dynamics simulations revealed that the PGP-Me chain appeared to exhibit behavior different from that of typical membrane lipids such as dimyristoylphosphatidylcholine (DMPC). The C-C bonds of the PGP-Me chain adopt alternative parallel and tilted orientations to the membrane normal as opposed to a DMPC chain where all of the C-C bonds tilt in the same way on average. This characteristic orientation causes the intertwining of PGP-Me chains, which plays an important role in the excellent thermal and high-salinity stabilities of archaeal lipid bilayers and membrane proteins.
基于全合成的对映选择性氘标记化合物的 H 核磁共振（NMR）研究，考察了水合双层膜中古菌脂磷脂酰甘油磷酸甲醚（PGP-Me）的甲基支链的平均构象。NMR 结果与分子动力学模拟相结合表明，PGP-Me 链的行为似乎与典型的膜脂（如二肉豆蔻酰磷脂酰胆碱（DMPC））不同。PGP-Me 链的 C-C 键采用交替的平行和倾斜取向相对于膜法线，而 DMPC 链中的所有 C-C 键平均以相同的方式倾斜。这种特征取向导致 PGP-Me 链的缠绕，这在古菌脂双层膜和膜蛋白的优异热稳定性和高盐稳定性中起着重要作用。
