盘基网柄菌早衰蛋白结构与功能生物信息学分析

Bioinformatics Analysis of Structure and Function of Presenilin in Dictyostelium discoideum

早衰蛋白(presenilin, PS)是γ分泌酶的组成成分,其突变可造成阿尔兹海默病(Alzheimer disease,AD)的形成。因PS所造成AD的发病机理较复杂,因而我们想探究一下模式生物盘基网柄菌(Dictyostelium discoideum)是否能够作为研究早衰蛋白的模型。从NCBI网站中得到盘基网柄菌早衰蛋白DdPsenA和DdPsenB氨基酸序列,随后利用ProtScale、ProtParam理化性分析工具、保守结构域、TMHMM2跨膜区分析网站、进化树软件MEGA6.0、二级结构PredictProtein以及三级结构SWISS-Model服务器对上述蛋白进行生物信息学分析。DdPsenA的氨基酸长度为622,是亲水性蛋白,其相对分子质量为69 502.79,等电点为4.53。DdPsenB的氨基酸长度为473,属于疏水性蛋白,其相对分子质量为52 558.74,等电点为4.49,与DdPsenA同属于Peptidase_A22B超家族。跨膜分析出DdPsenA和DdPsenB均有8个跨膜区。DdPsenA与人类presenilin-2序列相似性为67%,Dd PsenB与人类presenilin-1序列相似性分别为60%。盘基网柄菌可以作为研究早衰蛋白功能和作用机制的模型。

Presenilin(PS)is a component ofγ-secretase,which mutation can cause the formation of Alzheimer’s disease(AD).Because the pathogenesis of AD caused by PS is more complex,we want to explore whether the model organism D.discoideum can be a model to study presenilin.The amino acid sequences of D.discoideum presenilins DdPsenA and DdPsenB were obtained from the NCBI website.Then we carried out the bioinformatics analyses of DdPsenA and Dd PsenB by ProtScale,ProtParam,conserved domain,TMHMM2,MEGA6.0,PredictProtein and SWISS-Model.The amino acid length of DdPsenA is 622,which is a hydrophilic protein with a relative molecular mass of 69 502.79 and an isoelectric point of 4.53.The amino acid length of DdPsenB is 473,which is a hydrophobic protein with a relative molecular mass of 52 558.74 and an isoelectric point of 4.49,belonging to Peptidase_A22 B super family as well as DdPsenA.DdPsenA and DdPsenB have eight transmembrane regions.The similarity of DdPsenA with presenilin-2 is 67%.The similarity of DdPsenB with presenilin-1 is 60%.D.discoideum can be used as a model for the investigation of the function and mechanism of presenilin.