Molecular cloning and expression of α-neoagarooligosaccharide hydrolase from Gilvimarinus agarilyticus JEA5

Abstract

Agar is major cell wall component of red algae, and mainly consists of agarose and agaropectin. Agarose, a polymer of D-galactose and 3,6 anhydro-L-galactose bonded by alternately by α 1-3 and β1-4-glycosidic linkages, can be degraded into neoagaro-oligosaccharieds (NAOSs) or agaro-oligosacchareds (AOSs). NAOSs are hydrolyzed into L-AHG and odd-numbered agarooligosaccharide by α-neoagaro oligosaccharide hydrolase (α –NAOSH). L-AHG exhibits various biological activities, including skin whitening, anti-inflammation and anticarcinogenic effects. Although α-NAOSHs play significant role in production of L-AHG, only a few research studies on NAOSHs have been conducted. Therefore, there is a need of more information related to α-NAOSHs. In this study, α-NAOSH from Gilvimarinus agarilyticus JEA5, designated as GaNH was biochemically characterized. The open reading frame of GaNH comprises of 1,113 bp which encodes 370 amino acids and belongs to glycoside hydrolase family 117. Recombinant GaNH protein has maximum activity at 35℃ and pH 7.0, and exhibits a strong dependence on the presence of MnCl2. Thin-layer chromatography revealed that GaNH hydrolyzed NAOSs into L-AHG and odd numbered agarooligosacchareds. Therefore, this study suggest the potential of GaNH in industrial