A Broad-Spectrum Polysaccharide Lyase CHa2 from Marine Metagenome Exhibits Dual Activities toward Glycosaminoglycans and Alginate

Polysaccharide lyase family 8 (PL8), which comprises glycosaminoglycans (GAGs) lyases, xanthan lyases, and alginate lyases, is an important family of Carbohydrate-Active Enzymes database. In this study, a PL8 family enzyme, CHa2, which can degrade GAGs and alginate, was identified. CHa2 exhibits the highest activity at 40/50 °C and pH 8.0, and the enzyme activities toward HA, CSA, CSC, CSD, CSE, alginate, polyM, and polyG are 54.6, 161.1, 204.0, 163.6, 66.1, 4.0, 4.1, and 0.3 U/mg, respectively. CHa2 degrades CS and HA to generate disaccharides and tetrasaccharides as the final products in the endolytic mode. And when degrading alginate, CHa2 prefers to catalyze the M-rich regions. Though they showed higher activity toward CS, the tetrasaccharides like ΔC-A, ΔA-A, and ΔD-A would resist the degradation of CHa2. The study of CHa2 provides a tool enzyme capable of selectively preparing specific structural functional oligosaccharides, which has potential application value in functional food, biomedical, and other fields.