Zhang Chuan, Yu Leilei, Zhai Qixiao, Zhao Ruohan, Wang Chen, Zhao Jianxin, Zhang Hao, Chen Wei, Tian Fengwei
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Foods. 2022 May 18;11(10):1462. doi: 10.3390/foods11101462.
Among the nutrients available to the human gut microbiota, the complex carbohydrates and glycosaminoglycans are important sources of carbon for some of the species of human gut microbiota. Glycosaminoglycan (heparin) from the host is a highly preferred carbohydrate for . To explore how gut microbiota can effectively use heparin as a carbon source for growth, we conducted a screening of the Carbohydrate-Active enzymes (CAZymes) database for lytic enzymes of the PL13 family and Research Center of Food Biotechnology at School of Food Science and Technology of Jiangnan University database of to identify novel glycosaminoglycan-degrading bacterial strains. Four species (, , , and ) that degraded heparin were selected for further studies. Analysis of the polysaccharide utilization sites of the four strains revealed that all of them harbored enzyme encoding genes of the PL13 family. Functional analysis revealed the activity of CAZymes in a medium containing heparin as the sole carbon source, suggesting their potential to degrade heparin and support growth. The four enzymes were heterologous expressed, and their enzymatic properties, kinetics, and thermal stability were determined. The lytic enzyme of had high enzymatic activity and thermal stability. The features that cause this high thermal stability were elucidated based on an examination of the three-dimensional structure of the protein. Our findings provide an important theoretical basis for the application of glycosaminoglycans and glycosaminoglycan-degrading enzymes in the medical and biotechnology industries, and an important scientific basis for precision nutrition and medical intervention studies using gut microbiota or enzymes as targets.
在人类肠道微生物群可利用的营养物质中，复合碳水化合物和糖胺聚糖是人类肠道微生物群某些物种重要的碳源。宿主来源的糖胺聚糖（肝素）是……高度偏爱的碳水化合物。为了探究肠道微生物群如何有效利用肝素作为生长的碳源，我们在碳水化合物活性酶（CAZyme）数据库中筛选了PL13家族的裂解酶，并在江南大学食品科学与技术学院食品生物技术研究中心的数据库中进行筛选，以鉴定新型糖胺聚糖降解细菌菌株。选择了四种降解肝素的物种（……、……、……和……）进行进一步研究。对这四种菌株的多糖利用位点分析表明，它们都含有PL13家族的酶编码基因。功能分析揭示了在以肝素作为唯一碳源的培养基中CAZyme的活性，表明它们具有降解肝素并支持生长的潜力。对这四种酶进行了异源表达，并测定了它们的酶学性质、动力学和热稳定性。……的裂解酶具有较高的酶活性和热稳定性。基于对该蛋白质三维结构的研究，阐明了导致这种高热稳定性的特征。我们的研究结果为糖胺聚糖和糖胺聚糖降解酶在医药和生物技术产业中的应用提供了重要的理论依据，也为以肠道微生物群或酶为靶点的精准营养和医学干预研究提供了重要的科学依据。
