Identification and Characterization of Marine Bacteria-Derived Chondroitinase CHa3 in the PL35 Family

作者：Wenwen Wang, Zeting Ning, Yameng Zhu, Bin Zeng, Xiaoyun Li, Changxin Wu, Yanzi Dong, Yuqing Li, Mengda Zhang, Jinhua Zheng, Bo Lian, Hongyan Qiu, Huanhuan Wang, Danrong Lu, Qingdong Zhang · 发表于：Journal of Agricultural and Food Chemistry · 年份：2025 · DOI：10.1021/acs.jafc.5c01795 · 被引用次数：3 · 研究领域：Proteoglycans and glycosaminoglycans research、Glycosylation and Glycoproteins Research、Silk-based biomaterials and applications

Chondroitinase (CSase) derived from microorganisms is valuable for structural studies and preparation of chondroitin sulfate (CS) oligosaccharides. In this study, a new chondroitinase C, CHa3, which belongs to the PL35 family, was identified. The optimal activity of CHa3 was observed in NaH 2 PO 4 –Na 2 HPO 4 buffer (pH 8.0) at 20 °C. Its specific activity toward chondroitin sulfate A, chondroitin sulfate C, chondroitin sulfate D, and chondroitin sulfate was 1.11, 4.78, 2.63, and 1.91 U/mg protein, respectively. CHa3 digests substrate chains, acts as an endolytic lyase, and shows a significant preference for C-unit-enriched substrates such as CSC; thus, it is classified as chondroitinase C. The catalytic activity of CHa3 was resisted by O/A/D/E units when the CS substrates were degraded and was resisted by 2- O sulfated regions when the heparin substrate was digested. Tetrasaccharides in the final products of CS, which were degraded by CHa3, included ΔC-A, ΔC-C, ΔC-D, and ΔC-E. The residues Tyr 267 and His 417 played crucial roles in the catalytic process, and Arg 109, Arg 116, Asn 212, Asn 213, Trp 214, and Ser 416 may participate in the binding process for CHa3. This study of CHa3 contributes to our understanding of the PL35 family and provides a foundation for investigating the structure of CS.