A small chimerically bifunctional monomeric protein:: Tapes japonica lysozyme
A small chimerically bifunctional monomeric protein:: Tapes japonica lysozyme
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DOI：
10.1007/s00018-003-3082-z
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发表时间：
2003-09-01
影响因子：
8
通讯作者：
Imoto, T
中科院分区：
文献类型：
--
作者：
Takeshita, K;Hashimoto, Y;Imoto, T
日本带鱼溶菌酶(13.8 kDa)是一种新的蛋白质。该蛋白与药用水母中具有异肽酶活性的不稳定酶有46%的同源性。基于这些数据，我们证实了日本血吸虫溶菌酶对三种底物：L-γ-谷氨酸-PNA、D-γ-谷氨酸-PNA和β-(γ-谷氨酸)-L-赖氨酸的水解活性。几丁质酶和异肽酶的最适pH分别为5.0和7.0。丝氨酸蛋白酶抑制剂对异肽酶活性有抑制作用，但对裂解酶和几丁质酶活性无抑制作用。此外，冷冻干燥只降低了异肽酶的活性，而裂解酶和几丁质酶的活性没有降低。我们认为日本血吸虫溶菌酶在不同的活性部位表达异肽酶和几丁质酶活性。
The lysozyme of the marine bilave Tapes japonica (13.8 kDa) is a novel protein. The protein has 46% homology with the destabilase from medicinal leech that has isopeptidase activity. Based on these data, we confirmed hydrolysis activity of T japonica lysozyme against three substrates: L-gamma-Glu-pNA, D-gamma-Glu-pNA, and epsilon-(gamma-Glu)-L-Lys. The optimal pH of chitinase and isopeptidase activity was 5.0 and 7.0, respectively. The isopeptidase activity was inhibited with serine protease inhibitor, but the lytic and chitinase activities were not. Moreover, only isopeptidase activity is decreased by lyophilization, but lytic and chitinase activities were not. We conclude that T. japonica lysozyme expresses isopeptidase and chitinase activity at different active sites.