Edmond H. Fischer Signal Transduction Laboratory, School of Life Sciences, Jilin University, Changchun 130012, China.
University of Edinburgh Institute (ZJU-UoE Institute), Zhejiang University, Haining 314400, China.
Molecules. 2023 Jan 20;28(3):1048. doi: 10.3390/molecules28031048.
Chitosanase CsnMY002 is a new type of enzyme isolated from that is used to prepare chitosan oligosaccharide. Although mutants G21R and G21K could increase Chitosan yield and thus increase the commercial value of the final product, the mechanism by which this happens is not known. Herein, we used molecular dynamics simulations to explore the conformational changes in CsnMY002 wild type and mutants when they bind substrates. The binding of substrate changed the conformation of protein, stretching and deforming the active and catalytic region. Additionally, the mutants caused different binding modes and catalysis, resulting in different degrees of polymerization of the final Chitooligosaccharide degradation product. Finally, Arg37, Ile145 ~ Gly148 and Trp204 are important catalytic residues of CsnMY002. Our study provides a basis for the engineering of chitosanases.
壳聚糖酶 CsnMY002 是从 中分离出的一种新型酶，用于制备壳寡糖。虽然突变体 G21R 和 G21K 可以增加壳聚糖的产量，从而提高最终产品的商业价值，但这种情况发生的机制尚不清楚。在这里，我们使用分子动力学模拟来探索 CsnMY002 野生型和突变体与底物结合时构象的变化。底物的结合改变了蛋白质的构象，拉伸和变形了活性和催化区域。此外，突变体导致不同的结合模式和催化，导致最终的 Chitooligosaccharide 降解产物的聚合度不同。最后，Arg37、Ile145~Gly148 和 Trp204 是 CsnMY002 的重要催化残基。我们的研究为壳聚糖酶的工程改造提供了依据。
