Gorbenko Galyna P, Trusova Valeriya, Mizuguchi Chiharu, Saito Hiroyuki
Department of Nuclear and Medical Physics, V.N. Karazin Kharkiv National University, 4 Svobody Sq, Kharkiv, 61022, Ukraine.
Department of Biophysical Chemistry, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto, 607-8414, Japan.
J Fluoresc. 2018 Sep;28(5):1037-1047. doi: 10.1007/s10895-018-2267-7. Epub 2018 Jul 15.
The effects of one of the amyloidogenic mutations of apolipoprotein A-I (apoA-I), G26R, on the thermal stability, structural dynamics and lipid-associating properties of the 1-83 N-terminal fragment of apoA-I (A83) have been investigated using the Förster resonance energy transfer (FRET) and molecular dynamics (MD) simulation. The measurements of FRET between the tryptophan residues of the single Trp variants of A83 as donors and the membrane-incorporated fluorescent probe 4-dimethylaminochalcone as an acceptor provided evidence for a less depth of A83/G26R penetration into phosphatidylcholine (PC) bilayer compared to WT counterpart. The unfolding MD simulations showed that G26R mutation destabilizes the overall structure of A83, with individual alpha-helices differing in their thermal stability. The MD simulations performed at physiological temperature revealed that A83 and A83/G26R differ in their conformational behavior in an aqueous solution, PC and PC/Cholesterol bilayers. These findings may prove of importance for deeper understanding of the key determinants of apoA-I amyloidogenesis.
载脂蛋白A-I（apoA-I）的一种淀粉样生成突变G26R对apoA-I 1-83 N端片段（A83）的热稳定性、结构动力学和脂质结合特性的影响，已通过Förster共振能量转移（FRET）和分子动力学（MD）模拟进行了研究。以A83单Trp变体的色氨酸残基作为供体，与膜结合的荧光探针4-二甲基氨基查耳酮作为受体进行FRET测量，结果表明，与野生型相比，A83/G26R穿透磷脂酰胆碱（PC）双层的深度较小。展开的MD模拟表明，G26R突变使A83的整体结构不稳定，各个α螺旋的热稳定性不同。在生理温度下进行的MD模拟显示，A83和A83/G26R在水溶液、PC和PC/胆固醇双层中的构象行为不同。这些发现可能对更深入理解apoA-I淀粉样生成的关键决定因素具有重要意义。
