title: Family 13 carbohydrate-binding module of alginate lyase from Agarivorans sp. L11 enhances its catalytic efficiency and thermostability, and alters its substrate preference and product distribution.
abstract: The carbohydrate-binding module (CBM) in polysaccharide hydrolases plays a key role in the hydrolysis of cellulose, xylan and chitin. However, the function of CBM in alginate lyases has not been elucidated. A new alginate lyase gene, alyL2, was cloned from the marine bacterium Agarivorans sp. L11 by using degenerate and site-finding PCR. The alginate lyase, AlyL2, contained an N-terminal CBM13 and a C-terminal catalytic family 7 polysaccharide lyase (PL7) module. To better understand the function of CBM13 in alginate lyase AlyL2, the full-length enzyme (AlyL2-FL) and its catalytic module (AlyL2-CM) were expressed in Escherichia coli and characterized. The specific activity and catalytic efficiency of AlyL2-FL were approximately twice those of AlyL2-CM. The half-lives of AlyL2-FL were 4.7-6.6 times those of AlyL2-CM at 30-50°C. In addition, the presence of CBM13 in AlyL2 changed its substrate preference and increased the percentage of disaccharides from 50.5% to 64.6% in the total products. This first report of the function of CBM13 in alginate lyase provides new insights into the degradation of alginate by marine microorganisms.
authors.affiliation: Key Laboratory of Marine Drugs, Chinese Ministry of Education; Shandong Provincial Key Laboratory of Glycoscience and Glycotechnology; School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China.
authors.forename: Shangyong
authors.initials: S
authors.lastname: Li
authors.affiliation: Key Laboratory of Marine Drugs, Chinese Ministry of Education; Shandong Provincial Key Laboratory of Glycoscience and Glycotechnology; School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Yang
authors.affiliation: Key Laboratory of Marine Drugs, Chinese Ministry of Education; Shandong Provincial Key Laboratory of Glycoscience and Glycotechnology; School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China.
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Bao
authors.affiliation: Key Laboratory of Marine Drugs, Chinese Ministry of Education; Shandong Provincial Key Laboratory of Glycoscience and Glycotechnology; School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Key Laboratory of Marine Drugs, Chinese Ministry of Education; Shandong Provincial Key Laboratory of Glycoscience and Glycotechnology; School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China.
authors.forename: Wengong
authors.initials: W
authors.lastname: Yu
authors.affiliation: Key Laboratory of Marine Drugs, Chinese Ministry of Education; Shandong Provincial Key Laboratory of Glycoscience and Glycotechnology; School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, PR China fhan@ouc.edu.cn.
authors.forename: Feng
authors.initials: F
authors.lastname: Han
mesh_terms: D000464:Alginates / Q000378:metabolism; D034241:Alteromonadaceae / Q000201:enzymology* / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D055162:Biocatalysis; D050260:Carbohydrate Metabolism; D002482:Cellulose / Q000378:metabolism; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D020723:Glucuronic Acid / Q000378:metabolism; D006603:Hexuronic Acids / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011133:Polysaccharide-Lyases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D002482:Cellulose; D011133:Polysaccharide-Lyases; C016158:poly(beta-D-mannuronate) lyase
keywords: alginate lyase; carbohydrate-binding module; catalytic activity; product distribution; thermostability