Cloning and characterization of a new κcarrageena

Authors: Xiaoyan Xu Shangyong Li Xuemei Yang Wengong Yu Feng Han

Publish Date: 2015/11/07

Volume: 14, Issue: 6, Pages: 1082-1086

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Abstract

κcarrageenan oligosaccharides exhibit various biological activities Enzymatic degradation by κcarrageenase is safe and controllable Therefore κcarrageenases have captured more and more attentions In this study a κcarrageenase encoding gene cgkX was cloned from Pseudoalteromonas sp QY203 with degenerate and inverse PCR It comprised an ORF of 1194 bp in length encoding a protein with 397 amino acid residues CgkX is a new member of glycoside hydrolase family 16 The deduced amino acid sequence shared a high similarity with CgkX of Pseudoalteromonas κcarrageenase however the recombinant CgkX showed different biochemical characteristics The recombinant enzyme was most active at pH 70 and 55°C in the presence of 300 mmol L−1 NaCl It was stable in a broad range of acidity ranging from pH 30 to pH 100 when temperature was below 40°C More than 80 of its activity was maintained after being incubated at pH 36–100 and 4°C for 24 h CgkX retained more than 90 of activity after being incubated at 40°C for 1 h EDTA and SDS 1 mmol L−1 did not inhibit its activity CgkX hydrolyzed κcarrageenan into disaccharide and tetrasaccharide as an endocleaver All these characteristics demonstrated that CgkX is applicable to both κcarrageenan oligosaccharide production and κcarrageenase structurefunction research

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