马方综合征突变型微纤维蛋白-Ⅰ基因蛋白模型的计算机构建和分析

Computer construction and analysis of protein models of mutatant fibrillin-1 gene in Marfan＇s syndrome

目的运用计算机建模分析中国马方综合征单纯晶状体脱位患者突变型微纤维蛋白-Ⅰ（FBN1）物理结构的改变，以阐明其在晶状体脱位发病机制中的作用。方法对照实验研究。运用SWISS—MODEL软件预测、SWISS-Pdb浏览器观察与分析野生型和R545C、R1530C突变型微纤维蛋白-Ⅰ的蛋白构型。结果与野生型微纤维蛋白-Ⅰ比较，突变型微纤维蛋白-Ⅰ具有显著的二维结构的改变。R545C突变型微纤维蛋白-Ⅰ造成α螺旋结构缺失、氢键距离缩短、蛋白表面水溶性改变和分子负电荷势能下降。R1530C突变型微纤维蛋白-Ⅰ造成氢键缺失、蛋白表面水溶性改变和分子负电荷势能上升。结论突变型微纤维蛋白-Ⅰ基因显著改变了该蛋白的二维结构，进一步支持了微纤维蛋白-Ⅰ在马方综合征晶状体脱位发病机制中具有一定作用的理论。

Objective Fibrillin-1, the major constituent of extracellular microfibrils, plays an important role in the molecular pathogenesis of Marfan syndrome （ MFS, #154700）. The aim of this study was to analyze protein models of the mutation of the fibrillin-1 （ FBN1 ） gene on Arg545Cys and Arg1530Cys which have been reported to cause predominant eetopia lentis in Chinese patients. Methods We constructed and analyzed the protein models of the mutant FBN1 gene on Arg545Cys and Arg1530Cys. Fibrillin-1 protein structures were predicted by SWISS-MODEL. Models were viewed in Swiss-Pdb Viewer. Results Computer construction and analysis of protein models of the mutant FBN1 gene revealed that the mutant Arg545Cys FBN1 protein had various changes on protein＇s secondary structure with an absence of a helix, decreased hydrogen bond distance, different protein surface solvent-accessibility and decreased negative electrostatic potential. The mutant Arg1530Cys FBN1 showed lost of hydrogen bonds, different protein surface solvent-accessibility and increased negative electrostatic potential. Conclusions Protein models of the mutant FBN1 gene shows significant alterations on the protein＇s secondary structure based on computer construction and analysis technology. This study provides further evidenee for the important effect of the mutant FBN1 on the pathogenesis of human ectopia lentis.