Zhao Yu, Jin Yang, Wei Shuang-Shuang, Lee Wen-Hui, Zhang Yun
Department of Animal Toxinology, Kunming Institute of Zoology, The Chinese Academy of Sciences, Kunming, Yunnan 650223, China.
Toxicon. 2005 Nov;46(6):635-40. doi: 10.1016/j.toxicon.2005.07.003. Epub 2005 Sep 12.
Amphibian skin secretions contain many bioactive compounds. In the present work, an irreversible serine protease inhibitor, termed baserpin, was purified for the first time from the skin secretions of toad Bufo andrewsi by successive ion-exchange and gel-filtration chromatography. Baserpin is a single chain glycoprotein, with an apparent molecular weight of about 60 kDa in SDS-PAGE. Baserpin is an irreversible inhibitor and effectively inhibits the catalytic activity of trypsin, chymotrypsin and elastase. SDS-stable baserpin-trypsin complex could be seen in SDS-PAGE indicates that it possibly belongs to the serpin superfamily. According to the association rates determined, baserpin is a potent inhibitor of bovine trypsin (4.6 x 10(6) M(-1) s(-1)), bovine chymotrypsin (8.9 x 10(6) M(-1) s(-1)) and porcine elastase (6.8 x 10(6) M(-1) s(-1)), whereas it shows no inhibitory effect on thrombin. The N-terminal sequence of baserpin is HTQYPDILIAKPXDK, which shows no similarity with other known serine protease inhibitors.
两栖动物的皮肤分泌物含有许多生物活性化合物。在本研究中，首次通过连续离子交换和凝胶过滤色谱法从中华大蟾蜍的皮肤分泌物中纯化出一种不可逆的丝氨酸蛋白酶抑制剂，命名为baserpin。Baserpin是一种单链糖蛋白，在SDS-PAGE中表观分子量约为60 kDa。Baserpin是一种不可逆抑制剂，可有效抑制胰蛋白酶、胰凝乳蛋白酶和弹性蛋白酶的催化活性。SDS-PAGE中可见SDS稳定的baserpin-胰蛋白酶复合物，表明它可能属于丝氨酸蛋白酶抑制剂超家族。根据测定的结合速率，baserpin是牛胰蛋白酶（4.6×10⁶ M⁻¹ s⁻¹）、牛胰凝乳蛋白酶（8.9×10⁶ M⁻¹ s⁻¹）和猪弹性蛋白酶（6.8×10⁶ M⁻¹ s⁻¹）的有效抑制剂，而对凝血酶没有抑制作用。Baserpin的N端序列为HTQYPDILIAKPXDK，与其他已知的丝氨酸蛋白酶抑制剂没有相似性。
