中文摘要：

目的通过生物信息学预测曼氏迭宫绦虫cathepsin L样蛋白酶（Smcathepsin L样蛋白酶）的生物学特征及其潜在功能和结构,为下一步Smcathepsin L样蛋白酶参与寄生虫和宿主相互作用过程研究提供依据。方法通过NCBI的ORF finder工具对Smcathepsin L样蛋白酶的开放阅读框（ORF）进行分析,利用Ex PASy网站进行蛋白的物理化学参数、信号肽、跨膜螺旋和潜在分子生物学功能的预测,通过NCBI/BLAST对蛋白保守功能域进行预测。从NCBI网站获取不同物种的cathepsin L样蛋白酶序列,并利用Vector NTI suit 8.0和Tree View软件进行分析。利用SWISS-MODEL网站和SPDBV4.10软件分析Smcathepsin L样蛋白酶的三维空间结构。结果 Smcathepsin L样蛋白酶是一个全长基因,编码336个氨基酸。蛋白由2个典型的cathepsin L样蛋白酶结构域组成,序列当中有信号肽,是一个稳定的可溶性蛋白分子。三维空间立体结构分析结果显示Smcathepsin L样蛋白酶是一个保守的蛋白。Smcathepsin L样蛋白酶编码氨基酸序列与细粒棘球绦虫、链状带绦虫、多房棘球绦虫和人的cathepsin L样蛋白酶基因的同源性分别是50%、50%、49%和46%。分子进化分析显示Smcathepsin L样蛋白酶与日本血吸虫、多房棘球绦虫和链状带绦虫亲源性更近,而与其他物种,例如原虫、线虫和哺乳动物亲源性较远。结论 Smcathepsin L样蛋白酶可能是一个潜在的分泌蛋白,该蛋白能在胞外发挥作用,即在寄生虫的消化、转移、入侵及宿主-寄生虫相互作用中起着重要的作用,是一个具有潜在研究价值的多功能分子。

英文摘要：

Objective To provide information and pave the way for further research on cathepsin L-like proteinase of Spirometra mansoni（Smcathepsin L-like proteinase） which may participate in the interaction between parasite and host. Methods The open reading frame of Smcathepsin L-like proteinase was identified with open reading frame（ORF） finder tool in NCBI website. Ex PASy website was used to predict the physical and chemical parameters of protein, signal peptide, transmembrane helices and potential molecular and biological functions. The conserved domains of the protein were detected by NCBI/BLAST home. In order to analyze the homology and phylogenetic tree, sequences of cathepsin L-like proteinase from various species were obtained from NCBI website, and the results were analyzed by Vector NTI suil 8.0 and Tree View software. The three-dimensional structure of Smcathepsin L-like proteinase was predicted by SWISSMODEL and analyzed by SPDBV 4.10. Results Smcathepsin L-like proteinase is full-length gene and encoded 336 amino acid residues. The protein is composed of 2 classic conserved domains with signal peptide and a stably soluble molecule. It has a conservative cathepsin L-like proteinase in three-dimensional structure.Smcathepsin L-like proteinase is homologous to cathepsin L-like proteinase from Echinococcusgranulosus,Taeniasolium, Echinococcus multilocularis and Homo sapiens with 50%, 50%, 49% and 46% identities,respectively. Smcathepsin L-like proteinase clustered with the L-like proteinase from the Schistosoma japonicum, Echinococcus multilocularis, and Taeniasolium, but not with other species like protozoon, trematode and mammal animals. Conclusions Smcathepsin L-like proteinase is a potential secreted protein, and play a role in extracellular environment, such as digestion, metastasis, invasion and parasite-host interaction. Therefore,Smcathepsin L-like proteinase could be a potential important target.