REMARKABLE ACTIVITY ENHANCEMENT OF THERMOLYSIN MUTANTS
REMARKABLE ACTIVITY ENHANCEMENT OF THERMOLYSIN MUTANTS
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DOI：
10.1016/0014-5793(95)00537-j
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发表时间：
1995-06-19
期刊：
影响因子：
3.5
通讯作者：
OOE, S
中科院分区：
文献类型：
--
作者：
KIDOKORO, S;MIKI, Y;OOE, S
大多数试图通过活性位点周围的氨基酸取代来修饰酶的性质的尝试都导致了生物活性的抑制，这表明天然酶的结构应该在进化上几乎是最优化的，以显示最高的活性。相反，我们发现了一个有趣的网站，一个众所周知的金属内肽酶，嗜热菌蛋白酶（EC。3.4.24.4），其中几乎所有的氨基酸置换引起水解活性的显著增加。活性与热稳定性呈负相关。底物结合位点周围的灵活性被认为是相关性的关键。自然界可能选择了这个位点上的氨基酸，这抑制了分子的灵活性，以牺牲活性为代价获得最高的热稳定性。
Most attempts to modify the properties of enzymes by amino acid substitution around the active sites have resulted in suppression of the biological activity, suggesting that the structure of natural enzymes should be almost optimized evolutionally to show the highest activity. In contrast, we found an interesting site of a well-known metalloendopeptidase, thermolysin (EC. 3.4.24.4), where almost all the amino acid replacement causes a remarkable increase in the hydrolytic activity. Negative correlation between the activity and the thermal stability was observed. The flexibility around the substrate binding site is suggested to be a key to the correlation. Nature may have selected the amino acid at this site, which suppresses the flexibility of the molecule, to get the highest thermal stability at the expense of the activity.