Matak Mehdi Youssefi, Moghaddam Majid Erfani
Department of Biophysics, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran.
Biochem Biophys Res Commun. 2009 Dec 11;390(2):201-4. doi: 10.1016/j.bbrc.2009.09.073. Epub 2009 Sep 23.
Understanding structural determinants in enzyme active site integrity can provide a good knowledge to design efficient novel catalytic machineries. Fusarium solani pisi cutinase with classic triad Ser-His-Asp is a promising enzyme to scrutinize these structural determinants. We performed two MD simulations: one, with the native structure, and the other with the broken Cys171-Cys178 disulfide bond. This disulfide bond stabilizes a turn in active site on which catalytic Asp175 is located. Functionally important H-bonds and atomic fluctuations in catalytic pocket have been changed. We proposed that this disulfide bond within active site can be considered as an important determinant of cutinase active site structural integrity.
了解酶活性位点完整性的结构决定因素可为设计高效的新型催化机制提供丰富的知识。具有经典三联体Ser-His-Asp的茄病镰刀菌角质酶是研究这些结构决定因素的一种很有前景的酶。我们进行了两次分子动力学模拟：一次是对天然结构进行模拟，另一次是对断裂的Cys171-Cys178二硫键进行模拟。该二硫键稳定了催化性Asp175所在的活性位点中的一个转角。催化口袋中功能重要的氢键和原子波动发生了变化。我们提出，活性位点内的这种二硫键可被视为角质酶活性位点结构完整性的一个重要决定因素。
