School of Food and Biological Engineering, Anhui Fermented Food Engineering Research Center, Hefei University of Technology, Hefei 230601, China.
Department of Microbiology, Faculty of Sciences, University of Granada, Granada 18071, Spain.
J Agric Food Chem. 2024 Nov 6;72(44):24587-24598. doi: 10.1021/acs.jafc.4c05070. Epub 2024 Oct 25.
A novel α-amylase gene (BAA) from was cloned into , designing two recombinant α-amylases to facilitate extracellular secretion. Following optimizing the expression conditions, the highest yield of BAA (88.12 mmol/L) was achieved upon 36 h induction and 5 ng/mL nisin concentration. Determining the enzymatic properties of BAA revealed its poor stability and activity at high temperatures, hindering its widespread application. Therefore, we used computer-aided design to generate a mutant, S275L, which exhibited significantly improved activity and thermostability: an 18.7% increase in enzymatic activity (3767.38 U/mg), a 10 °C increase in optimal temperature, and a 49.2% improvement in stability at 60 °C. Molecular dynamics simulations and force analysis confirmed these enhancements. Finally, the mutant S275L's potential was further analyzed for starch hydrolysis on poultry feed. Therefore, the mutant S275L holds promising as an enzyme agent for enhanced feed digestibility and quality.
从 中克隆了一种新型的α-淀粉酶基因（BAA），设计了两种重组α-淀粉酶以促进细胞外分泌。在优化表达条件后，在 36 小时诱导和 5 ng/mL 乳链菌肽浓度下，BAA 的最高产量达到 88.12 mmol/L。确定 BAA 的酶学性质表明，其在高温下稳定性和活性差，限制了其广泛应用。因此，我们使用计算机辅助设计生成了一个突变体 S275L，其表现出显著提高的活性和热稳定性：酶活性提高了 18.7%（3767.38 U/mg），最适温度提高了 10°C，在 60°C 时稳定性提高了 49.2%。分子动力学模拟和力分析证实了这些增强。最后，进一步分析了突变体 S275L 在禽用饲料淀粉水解中的潜力。因此，突变体 S275L 有望成为增强饲料消化率和质量的酶制剂。
