【摘要】 为了探讨α－ 辅肌动蛋白与甘油二酯（ＤＧ）／ 棕榈油酸（ＰＡ） 的作用机制，利用荧光能量转移、酶切及ＦＴＩＲ 等方法研究了α－ 辅肌动蛋白与ＤＧ／ＰＡ 的作用特性及其构象变化。结果表明，α－ 辅肌动蛋白与外源ＰＡ 有较弱的结合， 且它们的结合具有较强的协同性； 高浓度的ＤＧ 对α－ 辅肌动蛋白与ＰＡ 的结合有一定促进作用。此外，与ＰＡ 结合后α－ 辅肌动蛋白酶切图谱发生了较大变化，其中央区两端的酶切位点受到较强的保护；ＤＧ 可以进一步延长α－ 辅肌动蛋白酶切的保护作用。ＦＴＩＲ 研究表明与ＰＡ 和ＤＧ／ＰＡ 脂质体结合后，α－ 辅肌动蛋白二级结构发生较大变化：结合ＰＡ 后，α－ 辅肌动蛋白部分α－ 螺旋结构转变为β－ 折叠结构；而ＤＧ 可进一步诱导β－ 转角结构的上升更多还原

【Abstract】 In order to further probe the mechanism of interaction of α-actinin with diacylglycerol(DG) /palmitic acid(PA), the binding characteristic and conformational change of α-actinin were investigated by means of fluorescence energy transfer, limited proteolysis and FTIR etc. The results showed that α-actinin was able to interact slightly and high synergetically with liposomes containing extrinsic palmitic acid, and the binding was enhanced by high content DG. Furthermore, it was found that there was significant change in the α-chymotrypsin digest map of α-actinin after binding to the liposomes containing palmitic acid, the cleavage sites on the junctions of central rod domain to N-terminal and C-terminal domains were effectively protected by its membrane-binding; DG was found to be able to prolong the protection effect of PA on the proteolytic sites in α-actinin. Analyzing by Fourier-transform infrared spectroscopy, it was found that the binding of α-actinin to PA vesicles transformed part of α-helical and random structure into β-sheet structure; while DG was able to further induce the secondary structural change of α-actinin in the presence of PA: significant increase in β-turn structure and slight decrease in random and β-sheet structure.更多还原