Li Yi, Deng Yihou, Li Yingjie, Wang Lushan
State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266000, China.
J Agric Food Chem. 2025 May 14;73(19):11855-11865. doi: 10.1021/acs.jafc.5c00257. Epub 2025 May 1.
Brown algae are the largest-producing macroalgae, and alginate lyase plays a key role in the green degradation and high-value conversion of brown algae. This study characterized a novel alginate lyase, VSAly7C, from the marine bacterium sp. 8-14, which belongs to the PL7_5 subfamily. Biochemical analysis suggested that VSAly7C is medium-temperature, neutral, and polyG-preferred, with enzyme activities of 2608.3 ± 27.3, 1453.2 ± 50.2, and 2545.2 ± 13.2 U/mg toward polyG, polyM, and sodium alginate, respectively. The minimal oligosaccharides VSAly7C could degrade were tetrasaccharides, and its major products were disaccharides and trisaccharides. Structural bioinformatic analysis of the VSAly7C active groove showed that the -1 to +3 subsite interaction network is crucial for determining the minimal oligosaccharides it can degrade. This study elucidates the catalytic properties, modes of action, and substrate recognition mechanisms of a novel alginate lyase, VSAly7C, which may be potentially applicable in alginate disaccharide and trisaccharide preparation.
褐藻是产量最大的大型藻类，而褐藻胶裂解酶在褐藻的绿色降解和高值转化中起着关键作用。本研究对一种来自海洋细菌sp. 8-14的新型褐藻胶裂解酶VSAly7C进行了表征，该酶属于PL7_5亚家族。生化分析表明，VSAly7C为中温、中性且偏好聚G，对聚G、聚M和海藻酸钠的酶活性分别为2608.3±27.3、1453.2±50.2和2545.2±13.2 U/mg。VSAly7C能够降解的最小寡糖为四糖，其主要产物为二糖和三糖。对VSAly7C活性凹槽的结构生物信息学分析表明，-1至+3亚位点相互作用网络对于确定其能够降解的最小寡糖至关重要。本研究阐明了新型褐藻胶裂解酶VSAly7C的催化特性、作用模式和底物识别机制，其可能潜在地应用于褐藻二糖和三糖的制备。
