小麦高分子量麦谷蛋白亚基1By15N端区同源建模与分子动力学模拟

Homology Modeling and Molecular Dynamics Simulations of N-terminal Domain of Wheat High Molecular Weight Glutenin Subunit 1By15

通过二级结构预测、折叠识别、同源建模和分子动力学模拟的方法,获得三个小麦高分子量麦谷蛋白亚基1By15N端区的三维结构模型。模型分析发现,y-型高分子量麦谷蛋白亚基N端的5个半胱氨酸具有两种成键模式,一种是Cys22和Cys44之间形成一个链内二硫键,N端剩余的三个半胱氨酸Cys10,45和55都是自由半胱氨酸用于形成链间二硫键;另一种是Cys22和Cys44,Cys10和Cys55之间形成两对链内二硫键,剩余一个Cys45作为自由半胱氨酸用于形成链间二硫键。

With the application of secondary structure prediction,fold-recognition,3D structure modeling and molecular dynamics simulation,three models for the N-terminal domain of HMW-GS 1By15 were built.Analysis of these models revealed two possible ways of disulfide bridges of the five cysteine residues in N-terminal domain of y-type HMW-GS.One way is that Cys22 and Cys44 form an intramolecular disulfide bridge,and the remaining three cysteine residues of N-terminal domain,Cys10,Cys45 and Cys55,act as free residues to form intermolecular disulfide bridges.The other way shows the existence of two intramolecular disulfide bridges between Cys22 and Cys44,Cys10 and Cys55,remaining Cys45 as a free residue for creating an intermolecular disulfide bridge.