Substrate specificity and inhibitor sensitivity of Ca2+/S100 dependent twitchin kinases
Substrate specificity and inhibitor sensitivity of Ca2+/S100 dependent twitchin kinases
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DOI：
10.1111/j.1432-1033.1996.454rr.x
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发表时间：
1996-12-15
期刊：
影响因子：
--
通讯作者：
Benian, GM
中科院分区：
文献类型：
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作者：
Heierhorst, J;Tang, XX;Benian, GM
肌联蛋白/肌颤蛋白样超家族的肌球蛋白相关巨蛋白激酶先前已涉及肌肉功能的调节，基于遗传和生理学研究。我们发现，重组的组成型活性秀丽隐杆线虫和Aesthesia twitchin激酶片段的催化活性和肽底物特异性不同，以及它们对萘磺酰胺抑制剂1-（5-chloronaphthalensulfonyl）-1H-hexahydro-1，4-diazepine（ML-7）和1-（5-iodonaphthalensulfonyl）-1H-hexahydro-1，4-diazepine（ML-9）的敏感性不同。组成型活性的Aaplasia twitchin激酶片段具有非常高的活性（V-max > 100 μ mol . min（-1）。mg（-1））。这些抽搐素激酶的自抑制形式可以通过S100 A1蛋白的二聚体形式（S100 A1（2））以Ca 2+依赖性方式激活。肌颤蛋白激酶S100 A1（2）-结合位点也可以结合Ca 2 +/钙调蛋白，但这两种激酶都不被钙调蛋白激活。这些数据提供了一个正在进行的晶体学研究tickin激酶片段的功能基础。
Myosin-associated giant protein kinases of the titin/twitchin-like superfamily have previously been implicated in the regulation of muscle function, based on genetic and physiological studies. We find that recombinant constitutively active Caenorhabditis elegans and Aplysia twitchin kinase fragments differ in their catalytic activities and peptide-substrate specificities, as well as in their sensitivities to the naphthalene sulfonamide inhibitors 1-(5-chloronaphthalenesulfonyl)-1H-hexahydro-1,4-diazepine (ML-7) and 1-(5-iodonaphthalenesulfonyl)-1H-hexahydro-1,4-diazepine (ML-9). The constitutively active Aplysia twitchin kinase fragment has a remarkably high activity (V-max > 100 mu mol . min(-1) . mg(-1)) towards some substrate peptides. The autoinhibited forms of these twitchin kinases can be activated in a Ca2+-dependent manner by the dimeric form of the S100A1 protein (S100A1(2)). The twitchin kinase S100A1(2)-binding site can also bind Ca2+/calmodulin but neither kinase is activated by calmodulin. The data provide a functional basis for the ongoing crystallographic study of twitchin kinase fragments.