INACTIVATION OF BOVINE TRYPSINOGEN AND CHYMOTRYPSINOGEN BY DIISOPROPYLPHOSPHOROFLUORIDATE
INACTIVATION OF BOVINE TRYPSINOGEN AND CHYMOTRYPSINOGEN BY DIISOPROPYLPHOSPHOROFLUORIDATE
复制标题
DOI：
10.1073/pnas.69.11.3312
复制
发表时间：
1972-01-01
影响因子：
11.1
通讯作者：
NEURATH, H
中科院分区：
文献类型：
--
作者：
MORGAN, PH;WALSH, KA;NEURATH, H
氟磷酸二异丙酯与胰蛋白酶原和胰凝乳蛋白酶原反应并抑制这两种酶原的潜在活性。反应遵循伪一级动力学，并且比相应酶的二异丙基磷酸化慢大约四个数量级。初始失活速率与试剂掺入的相关性表明，酶原失活是由每摩尔蛋白质掺入1摩尔有机磷酸盐引起的。从胰蛋白酶原的活性位点区域分离的肽占最初存在于[14 C]二异丙基磷酰基酶原中的标签的60%以上。可以得出结论，胰蛋白酶原的活化损失是由于丝氨酸183的烷基磷酸化。有人提出，降低反应性的酶原，相比的酶，主要反映了低效的结合底物和抑制剂，和Ser183的活性位点存在于胰蛋白酶原中的活化状态。
Diisopropylphosphorofluoridate reacts with trypsinogen and chymotrypsinogen and inhibits the potential activity of both zymogens. The reactions follow pseudo first-order kinetics and proceed approximately four orders of magnitude slower than diisopropylphosphorylation of the corresponding enzymes. Correlation of initial rates of inactivation with incorporation of the reagent indicates that zymogen inactivation results from incorporation of 1 mol of organic phosphate per mol of protein. Peptides isolated from the active-site region of trypsinogen account for more than 60% of the label originally present in the [14C]diisopropylphosphoryl zymogen. It is concluded that loss of activation of trypsinogen is due to alkylphosphorylation of Ser183. It is proposed that reduced reactivity of the zymogen, as compared to the enzyme, primarily reflects inefficient binding of substrates and inhibitors, and that Ser183of the active site exists in trypsinogen in an activated state.