Expression and Characterization of a Novel β‑Porphyranase from Marine Bacterium Wenyingzhuangia fucanilytica: A Biotechnological Tool for Degrading Porphyran
journal contributionposted on 08.08.2019, 21:13 by Yuying Zhang, Yaoguang Chang, Jingjing Shen, Changhu Xue
Porphyra is one of the most consumed types of red algae. Porphyran is the major polysaccharide extracted from Porphyra, and it is composed of alternating 4-linked α-l-galactopyranose-6-sulfate (L6S) and 3-linked β-d-galactopyranose (G) residues. β-Porphyranases are promising tools for degrading porphyran; however, few enzymes have been reported, and the biochemical properties of porphyranases are still unclear. Here, a novel GH16 β-porphyranase, designated as Por16A_Wf, was cloned from Wenyingzhuangia fucanilytica and expressed in Escherichia coli. Its biochemical properties and hydrolysis pattern were characterized. Por16A_Wf exhibited stable activity on a wide pH scale from 3.5 to 11.0. Glycomics analysis using LC-MS revealed that Por16A_Wf specifically hydrolyzed the glycosidic linkage of G-L6S, whereas it tolerated 3,6-anhydro-α-l-galactopyranose and methyl-d-galactose in −2 and +2 subsites, respectively. Por16A_Wf could be applied as a biotechnological tool for tailoring porphyran, which would serve in directional preparation of its disaccharide, producing products with various molecular weights and facilitating investigation of the structural heterogeneity of Porphyra polysaccharides.