Serra Gustavo Marques, Siqueira Andrei Santos, de Molfetta Fábio Alberto, Santos Agenor Valadares, Xavier Luciana Pereira
Laboratório de Biotecnologia de Enzimas e Biotransformações, Instituto de Ciências Biológicas, Universidade Federal do Pará-UFPA, Belém 66075-110, Brazil.
Laboratório de Tecnologia Biomolecular, Instituto de Ciências Biológicas, Universidade Federal do Pará-UFPA, Belém 66075-110, Brazil.
Microorganisms. 2023 Apr 11;11(4):998. doi: 10.3390/microorganisms11040998.
Cyanobacteria are rich sources of secondary metabolites and have the potential to be excellent industrial enzyme producers. β-glucosidases are extensively employed in processing biomass degradation as they mediate the most crucial step of bioconversion of cellobiose (CBI), hence controlling the efficiency and global rate of biomass hydrolysis. However, the production and availability of these enzymes derived from cyanobacteria remains limited. In this study, we evaluated the β-glucosidase from CACIAM 03 (MaBgl3) and its potential for bioconversion of cellulosic biomass by analyzing primary/secondary structures, predicting physicochemical properties, homology modeling, molecular docking, and simulations of molecular dynamics (MD). The results showed that MaBgl3 derives from an N-terminal domain folded as a distorted β-barrel, which contains the conserved His-Asp catalytic dyad often found in glycosylases of the GH3 family. The molecular docking results showed relevant interactions with Asp81, Ala271 and Arg444 residues that contribute to the binding process during MD simulation. Moreover, the MD simulation of the MaBgl3 was stable, shown by analyzing the root mean square deviation (RMSD) values and observing favorable binding free energy in both complexes. In addition, experimental data suggest that MaBgl3 could be a potential enzyme for cellobiose-hydrolyzing degradation.
蓝藻是次生代谢产物的丰富来源，有潜力成为优秀的工业酶生产者。β-葡萄糖苷酶广泛应用于生物质降解过程，因为它们介导了纤维二糖生物转化的最关键步骤，从而控制生物质水解的效率和整体速率。然而，源自蓝藻的这些酶的产量和可得性仍然有限。在本研究中，我们通过分析一级/二级结构、预测理化性质、同源建模、分子对接以及分子动力学（MD）模拟，评估了来自CACIAM 03的β-葡萄糖苷酶（MaBgl3）及其对纤维素生物质进行生物转化的潜力。结果表明，MaBgl3源自一个折叠成扭曲β-桶状的N端结构域，其中包含在GH3家族糖基化酶中常见的保守His-Asp催化二元组。分子对接结果显示，与Asp81、Ala271和Arg444残基存在相关相互作用，这些残基在MD模拟过程中有助于结合过程。此外，通过分析均方根偏差（RMSD）值并观察两种复合物中有利的结合自由能，表明MaBgl3的MD模拟是稳定的。此外，实验数据表明MaBgl3可能是一种潜在的纤维二糖水解降解酶。
