中文摘要：

目的原核表达、分离纯化毛首鞭形线虫（Trichuris trichiura）丝氨酸蛋白酶抑制剂1（TtSer-pinl），并观察其对蛋白酶的抑制作用。方法从毛首鞭形线虫成虫cDNA中扩增TtSerpinl编码序列（GenBank登录号为MF401634），将其连接入原核表达载体，构建重组质粒pET32a-suno／TtSerpin1。将重组质粒转化人大肠埃希菌（Escherichia coli）BL21（DE3）中，用异丙基．B—D．硫代半乳糖苷诱导TtSerpinl融合蛋白表达。表达的包涵体蛋白经变性、复性、镍亲和层析纯化、SUMO蛋白酶酶切融合标签后获得rTtSerpin1。用发色底物法检测其对人组织蛋白酶G、中性粒细胞弹性蛋白酶、蛋白酶3、纤溶酶和胰蛋白酶，猪胰蛋白酶、胰弹性蛋白酶及牛α-胰糜蛋白酶的抑制作用。结果成功构建了重组质粒pET32a—sumo／TtSerpinl．并在E．coli中成功表达。表达产物主要为包涵体．复性、纯化后的rTtSerpinl具有较好的蛋白酶抑制活性。1000nmol／L的rTtSerpinl对人组织蛋白酶G（100nmd／L）、中性粒细胞弹性蛋白酶（10nmol／L）、蛋白酶3（200nmol／L），猪胰弹性蛋白酶（10nrilol／L），牛α-胰糜蛋白酶（1nmol／L）的蛋白酶活性抑制率分别为60．89％、82．84％、21．21％、58．32％、96．98％，但对人纤溶酶、胰蛋白酶及猪胰蛋白酶抑制活性较弱。rTrSerpinl对人组织蛋白酶G及中性粒细胞弹性蛋白酶的抑制常数（Ki）分别为（949．80±91．51）、（242．70±53．41）nmol／L。结论rTtSerpinl对多种丝氨酸蛋白酶具有较强抑制作用。

英文摘要：

Objective To express, identify and characterize the serine protease inhibitory activity of Trichuris trichiura serine protease inhibitor 1 （TtSerpinl）. Methods The nucleotide sequence encoding for TtSerpinl （GenBank No. MF401634） was amplified from adult T. trichiura eDNA and ligated into pET32a-sumo vector to construct the recombinant plasmid pET32a-sumo/TtSerpinl. The positive recombinant plasmid was transferred into Escherichia coli BL21 （DE3） and expressed with 1PTG induction. After denaturation, refolding, purification by Ni-NTA resin affinity chromatography and cleaving fusion tag by SUMO protease on the resin, a single stage chromogenic assay was used to detect the inhibitory activity of rTtSerpinl against sefine proteases. Results The recombinant plasmid pET32a- sumo/TtSerpinl was constructed successfully. The fusion protein expressed in E. coli was insoluble and became aggregated as the inclusion body. The purified TtSerpinl after refolding showed inhibitory activity against serine proteases. At a concentration of 1 000 nmol/L, rTtSerpinl inhibited the enzymatic activity of human cathepsin G （100 nmol/L）, human neutrophil elastase （10 nmol/L）, human proteinase 3 （200 nmol/L）, porcine pancreatic elastase （10 nmol/L） and bovine pancreatic α-chymotrypsin （1 58.32%, and 96.98%, respectively, but it showed a weaker porcine trypsin （1 nmol/L） and human fibrinolytic enzyme （5 neutrophil elastase with a Ki value of （949.80 ± 91.51） and nmol/L） by approximately 60.89%, 82.84%, 21.21%, inhibitory activity against human trypsin （1 nmol/L）, nmol/L）, rTtSerpinl inhibited human cathepsin G and （242.70 ± 53.41） nmol/L, respectively. Conclusion TtSerpinl shows an inhibitory activity against multiple serine proteases