The methylamine reactive site and protease inhibition in alpha 2-macroglobulin.
The methylamine reactive site and protease inhibition in alpha 2-macroglobulin.
复制标题
α2-巨球蛋白中的甲胺反应位点和蛋白酶抑制。
DOI：
10.1111/j.1749-6632.1983.tb18106.x
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发表时间：
1983
影响因子：
5.2
通讯作者：
Eccleston,E
中科院分区：
文献类型：
--
作者：
Howard,JB;Swenson,R;Eccleston,E
亲核试剂、NH4+、肼和甲胺对 α2M 的失活遵循伪一级（总体二级）速率。然而，亲核试剂的掺入速率是双相的，较快的速率与失活一致。甲胺使 α2M 完全失活，从而防止蛋白酶裂解 α2M。蛋白酶裂解的丧失比甲胺掺入慢，但与失活平行。我们的结果与连续构象变化导致 alpha 2M 蛋白酶结合和失活的复杂模型一致。我们的结果表明，通过硫醇酯的氨解将蛋白酶与α2M交联并不是蛋白酶失活所必需的。
The inactivation of alpha 2M by the nucleophiles, NH4+, hydrazine, and methylamine, follows pseudo-first-order (second order, overall) rates. The rate of incorporation of nucleophiles however, is biphasic with the faster rate consistent with inactivation. Protease cleavage of alpha 2M is prevented by complete inactivation of alpha 2M by methylamine. Loss of protease cleavage is slower than methylamine incorporation but parallels inactivation. Our results are consistent with a complex model of sequential conformation changes leading to binding and inactivation of proteases by alpha 2M. Our results suggest that cross-linking of the protease to alpha 2M by aminolysis of the thiolester is not required for inactivation of the protease.