Huidobro-Toro J P, Chelala C A, Musacchio J M
Biochem Pharmacol. 1982 Oct 15;31(20):3323-8. doi: 10.1016/0006-2952(82)90568-8.
Black widow spider venom gland extract was found to contain significant peptidase activity. Aliquots of the venom gland extract incubated at 37 degrees inactivated substance P (SP) and bradykinin but not angiotensin II or the enkephalins. The peptide inactivation was proportional to the duration of the incubation and the amount of extract used. Analysis of the peptides on high pressure liquid chromatography demonstrated that the loss in biological activity of SP and bradykinin in the longitudinal muscle of the guinea pig ileum was correlated with cleavage of the peptides into several fragments. Kinetic studies revealed that SP was initially split into two fragments but that these products underwent further degradation into smaller peptides. The optimal pH for the peptidase activity was 6.5. At 0 degree the enzymatic activity was undetectable, and it was irreversibly destroyed by incubation at 100 degrees for 5 min or by pretreatment of the extract with 100 microM diisopropyl fluorophosphate. In addition, the gland extract preparation hydrolyzed artificial substrates designed to detect trypsin or chymotrypsin-like activity.
研究发现黑寡妇蜘蛛毒腺提取物含有显著的肽酶活性。将毒腺提取物的等分试样在37℃孵育可使P物质（SP）和缓激肽失活，但不会使血管紧张素II或脑啡肽失活。肽的失活与孵育时间和所用提取物的量成正比。对豚鼠回肠纵肌中的肽进行高压液相色谱分析表明，SP和缓激肽生物活性的丧失与肽裂解成几个片段有关。动力学研究表明，SP最初被分解为两个片段，但这些产物会进一步降解为更小的肽。肽酶活性的最适pH为6.5。在0℃时无法检测到酶活性，在100℃孵育5分钟或用100微摩尔二异丙基氟磷酸预处理提取物会使其不可逆地失活。此外，腺体提取物制剂可水解用于检测胰蛋白酶或胰凝乳蛋白酶样活性的人工底物。
