人腺体激肽释放酶2同源模建及与底物分子对接三研究-生物学、生理学专业毕业论文.pdf.docx

’，，一嗲，坶≯．参兰州大学硕士研究生论文 ’，，一嗲，坶≯．参 兰州大学硕士研究生论文 杨丹 摘 要 人腺体激肽释放酶2(hK2)由于其在前列腺癌检测治疗等方面的潜在临床应用 价值，近年来受到了广泛研究。但由于hK2的自水解作用，获得其晶体结构非常困 难，这使得对其结构功能间的关系认识较少。为了探讨hK2的结构活性关系，为后 续的以hK2为靶标的药物设计等研究提供理论基础。本课题以其家族同源性高的成 员为模板，利用同源模建的方法构建出hK2的模型，随后用分子动力学计算对模型 进行进一步优化。并用模型优化后的模型与其底物进行了分子对接实验，探讨了其 与底物的作用方式。 经验证，通过同源模建所构建的模型较为可靠。该模型与其同家族的成员间极为 相似，主要的区别存在于表面的loop区，特别是kallikrein loop，kallikrein loop的结 构影响了底物与hK2的接近。其催化三联体高度保守，侧链走向与同家族成员一致。 此外，保守的5对二硫键稳定了酶的整体结构。通过对接实验，我们发现其S1结合 口袋的组成与hKl、hK4、hK5和hK6有一定相似性，结合口袋中的氨基酸与底物 P1位点Arg胍基间形成广泛的氢键联系，为底物专一性提供了结构基础。 通过本课题的研究，使得对hK2结构功能间的关系，与底物识别的方式有了一 定认识，这些信息将对随后的研究提供支持和指导。 关键词：hK2；同源模建；分子对接；分子动力学 ‘f孳j毫净?凄兰州大学硕士研究生论文 ‘f孳j毫净?凄 兰州大学硕士研究生论文 杨丹 ABSTRACT As the potential clinical usefulness of human glandular kallikrein 2，it was well studied in recent years．But it’S difficult to acquire the crystal structure of hK2，due to its autocatalysis，thus the knowledge of its structure·function relationship is still not clear．In order to exploring this relationship，for further studying and designing new substances， The homology model of hK2 was constructed by homology modeling and optimized by molecular dynamic simulation,finally docked with the known substrate S-2302，for discovering the binding mechanism． The hK2 homology model WaS reliable after analysis．Its general structural organization WaS quite similar to other members of kallikrein family．Although，there were appreciable differences observed in the surface loop regain,especially in the kallikrein loop．which may affect the substrate to approach hK2．The active-site triad WaS highly conserved．The side chain orientation WaS identical with family members．Also the overall structure of hK2 Was stabilized by 5 disulfide bonds that formed by ten conserved Cys residues．The docking study revealed that S 1 pocket was similar晰th hKl，hK4，hK5 and hK6 at some extent．The Arg in substrate P 1 was extensively formed hydrogen bond to the residues of bind pocket，thus provide structure foundation of substrate specificity． This work