胎盘特异蛋白8的理化性质及其分子结构分析  

Physicochemical properties and molecular structure of placenta-specific protein 8

作　　者：刘建兵[1,2] 李文龙 蔡芳芳 崔小华 郝建卿[1,2] 师如意 林晓雨 李莉[1,2] LIU Jian-bing;LI Wen-long;CAI Fang-fang;CUI Xiao-hua;HAO Jian-qing;SHI Ru-yi;LIN Xiao-yu;LI Li(Department of Medical Cell Biology and Genetics,School of Basic Medical Sciences,Shanxi Medical University,Taiyuan 030001,Shanxi Province,China;不详)

机构地区：[1]山西医科大学基础医学院医学细胞生物与遗传学教研室,山西太原030001 [2]山西医科大学细胞生理学教育部重点实验室,山西太原030001 [3]山西医科大学基础医学院,山西太原030001

出　　处：《中国生物制品学杂志》2021年第10期1178-1183,共6页Chinese Journal of Biologicals

基　　金：山西医科大学博士启动金项目(03201502);山西省教育厅高校科技创新计划(2020L0189)。

摘　　要：目的对胎盘特异蛋白8(placenta-specific protein 8,PLAC8)的理化性质及其分子结构进行分析,为进一步研究PLAC8的功能及其作用机制提供新的思路和方向。方法应用ProtParam和Protscale,SignalP,TMHMM,PSORTⅡ,OPMA和Conserved Domain,NetNGlyc、YinOYang和Netphos,STRING等软件,分析PLAC8的理化性质、信号肽结构、跨膜结构、亚细胞定位、二级结构和结构域、蛋白翻译后位点修饰以及预测相互作用蛋白,并构建系统进化树。结果PLAC8的相对分子质量为12 440.52,分子式为C_(524)H_(832)N_(154)O_(157)S_(22),理论等电点(PI)=7.34,不稳定指数为38.99,亲水性平均总值为0.125,脂肪指数为57.65,整体亲水区大于疏水区。PLAC8不具有信号肽和跨膜结构域;定位于细胞外基质(44.4%)、细胞质(33.3%)、液泡(11.1%)和细胞核(11.1%);二级结构主要由α-螺旋(47%)组成;保守结构域由77个氨基酸残基构成;有5个O-糖基化位点和4个磷酸化位点;互作蛋白主要包括中性粒细胞弹性蛋白酶(elastase,neutrophil expressed,ELANE;score:0.913)、组蛋白酶G(cathepsin G,CTSG;score:0.913)、组蛋白酶(cathepsin G,CTSC;score:0.910)等10个蛋白。人PLAC8的蛋白序列与黑猩猩相似度最高,与家兔相似度最低。结论 PLAC8是一种碱性蛋白,主要定位于细胞外基质,且具有多个糖基化和磷酸化修饰位点,能够与多个蛋白形成互作网络;人PLAC8的蛋白序列与黑猩猩相似度最高。本研究将为进一步探讨PLAC8在生命活动中的功能及其作用机制提供了新的思路。Objective To analyze the physicochemical properties and molecular structure of placenta-specific protein 8(PLAC8)so as to provide a new ideal and method for further study on the function and action mechanism of PLAC8.Methods The physicochemical properties,signal peptide structure,transmembrane structure,subcellular location,secondary structure and domain,post-translational site modification and protein interaction network of PLAC8 were analyzed by using software such as ProtParam,Protscale,SignalP,TMHMM,PSORT Ⅱ,OPMA,Conserved Domain,NetNGlyc,YinOYang,Netphos and STRING,based on which a phylogenetic tree was constructed.Results The relative molecular mass of PLAC8 was 12 440.52,while the molecular formula was C_(524)H_(832)N_(154)O_(157)S_(22),the theoretical isoelectric point(PI)was 7.34,the instability index was 38.99,the average total hydrophilic value was 0.125,the aliphatic index was 57.65, and the hydrophobic region was less than the hydrophilic region.PLAC8 had no signal peptide or transmembrane domain,which was localized in the extracellular matrix(44.4%),cytoplasm(33.3%),vesicles(11.1%)and nucleus(11.1%).The secondary structure of PLAC8 consisted mainly of α-helix(47%),while the conserved domain consisted of 77 amino acid residues.There were five O-glycosylation sites and four phosphorylation sites in PLAC8.PLAC8 interacted with 10 proteins including ELANE,CTSG and CTSC.The protein sequence of human PLAC8 showed the highest similarity with that of chimpanzee and the lowest similarity with that of rabbit.Conclusion PLAC8 is an alkaline protein which is primarily localized in the extracellular matrix and has multiple glycosylation and phosphorylation modification sites that allow it to form interacting networks with multiple proteins.Human PLAC8 shares the highest sequence similarities with that of chimpanzee.These results will provide new ideas for further study on the function and mechanism of PLAC8 in life activities.

关 键 词：胎盘特异蛋白8 理化性质 分子结构 生物信息学 

分 类 号：R34[医药卫生—基础医学]