Hagihara S, Komori Y, Tu A T
Comp Biochem Physiol C Comp Pharmacol Toxicol. 1985;82(1):21-7. doi: 10.1016/0742-8413(85)90204-x.
In our effort to identify the proteolytic specificity of various hemorrhagic toxins isolated from western diamondback rattlesnake venom, hemorrhagic toxin b was isolated in homogeneous form by previously published methods. Hemorrhagic toxin b hydrolyzed glucagon, producing six fragments. The proteolytic sites were identified as Thr(5)-Phe(6), Thr(10)-Ser(11), Asp(15)-Ser(16), Asp(21)-Phe(22) and Try(25)-Leu(26). When oxidized insulin B chain was used, proteolysis occurred at four sites: Asn(3)-Gln(4), His(10)-Leu(11), Tyr(16)-Leu(17) and Gly(23)-Phe(24). The proteolytic specificity of hemorrhagic toxin b is quite different from those of the nonvenom proteases such as thermomycolin, aspergillopeptidase c, alkaline protease from Aspergillus flavus, elastase, subtilisin and papain.
为了确定从西部菱斑响尾蛇毒液中分离出的各种出血毒素的蛋白水解特异性，我们采用先前发表的方法以均一形式分离出了出血毒素b。出血毒素b可水解胰高血糖素，产生六个片段。蛋白水解位点被确定为苏氨酸(5)-苯丙氨酸(6)、苏氨酸(10)-丝氨酸(11)、天冬氨酸(15)-丝氨酸(16)、天冬氨酸(21)-苯丙氨酸(22)和色氨酸(25)-亮氨酸(26)。当使用氧化胰岛素B链时，蛋白水解发生在四个位点：天冬酰胺(3)-谷氨酰胺(4)、组氨酸(10)-亮氨酸(11)、酪氨酸(16)-亮氨酸(17)和甘氨酸(23)-苯丙氨酸(24)。出血毒素b的蛋白水解特异性与非毒液蛋白酶如嗜热栖热放线菌蛋白酶、曲霉肽酶c、黄曲霉碱性蛋白酶、弹性蛋白酶、枯草杆菌蛋白酶和木瓜蛋白酶的蛋白水解特异性有很大不同。
