亚天花粉蛋白突变体(R163H n-TCS和R163Q n-TCS)的晶体结构研究

用悬滴汽相扩散法得到了Ｒ１６３Ｈｎ－ＴＣＳ和Ｒ６１３Ｑｎ－ＴＣＳ的晶体，Ｍａｒ－Ｒｅｓｅａｒｃｈ面探测器系统上分别收集了０．２００和０．２０５ｎｍ分辨率的Ｘ－射线衍射数据，采用同晶差值傅立叶法解析结构，用Ｘ－ＰＬＯＲ软件包进行修正，最后的晶体学Ｒ因子分别为０．１８４和０．１８５，键长偏差分别为０．００１３ｎｍ和０．００１４ｎｍ，键角偏差分别为２．５９０和２．８１５，结构测定显示Ｒ１６３Ｈｎ－ＴＣＳ

CRYSTAL STRUCTURE OF R163H n-TCS and R163Q n-TCS

Crystals of R163H n-TCS and R163Q n-TCS were grown by hanging drop vapor diffusion technique. X-ray diffraction data of two crystals were collected respectively to 0.200 and 0.205nm,on Mar-Research IP. The Structure were determined by Difference Fourier Method, the rms deviations of bond length were 0.0013nm and 0.0014nm,and r.m.s deviations of bond angle are 2.590° and 2.825° respectively. Structure determination indicates that there is no obvious change between R163H n-TCS, R163Q n-TCS and the original n-TCS, the structures of the active pocket remain unchanged. Biochemical analysis shows that suggests R163H n-TCS has the glycosidase activity while R163Q n-TCS has no. All findings suggest that the R163 is one of the critical residuels for N-glycosidase activity of n-TCS.