论文部分内容阅读
目的:对人钙激活中性蛋白酶(calpain)的2个亚家族成员calpain-1和calpain-2进行功能的比较分析。方法:以美国生物技术国家中心(NCBI)的蛋白质数据库获取人calpain-1和calpain-2的参考序列号(Ref-Seq)和氨基酸序列,通过UniProt数据库检索2个蛋白的一般蛋白质功能注释,获取相关结构域信息;利用DNA-MAN软件对结构域进行序列比对,用蛋白质结构数据(PBD)和蛋白修饰数据库(PhosphoSit Plus)进行修饰位点空间分布的分析及用String9.0软件进行蛋白质-蛋白质相互作用分析。结果:结构域比对分析显示,人calpain-1和calpain-2的钙蛋白酶催化结构域保守性程度高,而EF-hand结构域的差异比较大;翻译修饰分析发现,2个蛋白的修饰有明显的不同,人calpain-1的修饰比较单一,仅发现在赖氨酸(K84)有乙酰化修饰,而calpain-2的修饰形式和位点相对多样,分布在分子表面、间隙内及分子内部。相互作用分析发现,与人calpain-1和calpain-2相互作用的蛋白质有少部分是相同的,而多数是不同的,分别与不同细胞活动有关。结论:人calpain-1和cal-pain-2的钙蛋白酶催化结构域是高度保守的,二者功能上差异主要是由于调控位点(EH-hand和翻译后修饰位点)的差异引起。
OBJECTIVE: To compare the functions of calpain-1 and calpain-2, two subfamilies of human calpain. Methods: The reference sequence numbers (Ref-Seq) and amino acid sequences of human calpain-1 and calpain-2 were obtained from the NCBI protein database. The general protein function annotations of two proteins were searched by UniProt database. Related domain information; DNA-MAN software for sequence alignment of the domain, the use of protein structure data (PBD) and protein modification database (PhosphoSit Plus) analysis of the spatial distribution of the modified sites and the use of String9.0 software for protein- Protein interaction analysis. Results: The alignment of the domains of calpain-1 and calpain-2 showed that the calpain-1 and calpain-2 catalytic domains were highly conserved and EF-hand domains were significantly different. The translational modifications showed that the modifications of two proteins Significantly different, human calpain-1 modification is relatively simple, only found in lysine (K84) acetylation, and calpain-2 modified forms and sites are relatively diverse, distributed in the molecular surface, interstitial and intramolecular . Interaction analysis found that a small part of the proteins interacting with human calpain-1 and calpain-2 were the same, but most of them were different and were related to different cell activities respectively. CONCLUSIONS: The calpain-1 and cal-pain-2 catalytic domains of calpain-1 are highly conserved and the functional differences between the two are mainly due to differences in regulatory sites (EH-hand and posttranslational modification sites).