RGD与特定形貌金红石表面相互作用的分子动力学模拟

发布时间：2018-04-25 22:25

本文选题：金红石 + 表面拓扑结构　；参考：《化工学报》2017年01期

【摘要】：精氨酸甘氨酸天冬氨酸(Arg-Gly-Asp,RGD)序列是细胞膜整合素受体与细胞外配体相结合的识别位点,利用其对材料表面进行仿生修饰可以提高植入体的生物相容性。采用全原子分子动力学方法,模拟研究了RGD与理想和具有不同深度凹槽结构的金红石型TiO_2(110)表面的结合模式和结合稳定性。研究结果表明,在纯水环境下,RGD在金红石表面存在锚定点是该序列中带负电的羧基基团与表面Ti原子直接键合的前提。凹槽侧壁表层的不饱和原子是RGD形成吸附的潜在作用点,故在金红石表面引入凹槽结构能在一定程度上影响该序列同基底之间的结合模式。当RGD通过羧基基团与槽底原子稳定键合之后,若剩余部分的长度足以触及至槽壁区域,则肽链中带正电的氨基或胍基基团与槽壁原子形成氢键的概率较大;若RGD通过两侧末端基团分别同槽底形成了稳定作用,则会显著抑制该序列与槽壁原子之间氢键的形成。RGD序列同金红石表面结合作用的强弱取决于结合点的数量以及相互作用的具体类型。
[Abstract]:Arginine glycine aspartic acid (Arg-Gly-AspRGD) sequence is a recognition site for the binding of integrin receptors to extracellular ligands. The biocompatibility of the implants can be improved by biomimetic modification on the surface of the materials. The bonding modes and bonding stability of RGD with rutile TiO210) surfaces with ideal and different depth grooves were studied by means of full atomic molecular dynamics. The results show that the anchoring point of RGD on the surface of rutile in pure water environment is the premise of direct bonding of negatively charged carboxyl groups with Ti atoms in the sequence. The unsaturated atoms in the surface layer of the side wall of the grooves are the potential sites for the adsorption of RGD, so the introduction of the grooves on the rutile surface can to some extent affect the binding mode between the series and the substrate. When RGD is bonded to the bottom atom by carboxyl group, if the remaining part is long enough to reach the groove wall, the positive amino or guanidine group in the peptide chain has a high probability of forming hydrogen bond with the groove wall atom. If RGD acts as a stabilizer through the end groups of the two sides of the channel, The binding of RGD sequence to rutile surface depends on the number of binding points and the specific type of interaction.
【作者单位】：哈尔滨工业大学材料科学与工程博士后流动站;哈尔滨工业大学机电工程学院;
【基金】：国家自然科学基金委员会创新研究群体科学基金项目(51521003) 中央高校基本科研业务费专项资金(AUGA5710058415) 中国博士后基金项目(2015M581439) 高等学校学科创新引智计划项目(B07018)~~
【分类号】：TQ134.11;R318.08

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