Characterization of the alpha-galactosidase of Paenibacillus sp. K1
- XIN Yong-ping, KONG Wen-tao, LU Wen-wei, KONG Jian
JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE). 2015, 50(01):
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A novel alpha-galactosidase encoded by agaP1 gene was amplilfied in the genome of Paenibacillus sp. K1 by CODEHOP PCR and Anchor-ligated PCR techniques. It was 2 190 bp in size and composed of 729 amino acid residues with 82.7 ku of predicted molecular weight,and pI 5.16. The AgaP1 was expressed in E.coli Origami B (DE3) and purified with His-tag chromatography column. The enzymic properties of alpha-galactosidase AgaP1 was analysized and showed optimum temperature of 40 ℃, optimal pH of 6.5-10, Km 0.75 mmol/L and Vmax 1.96 μmol·min-1·mg-1. The AgaP1 activity could be improved one to three folds by Fe2+, Mg2+, Ca2+, K+ and glycerol, whereas Cu2+, Zn2+, Fe3+ and glutathione could completely inhibit the AgaP1 activity. SDS-PAGE revealed a single band of 80 ku, consistant with the predicted size, while two bands of 150 ku and 440 ku was observed on the native-PAGE gel, corresponding to two and six oligomers of AgaP1. All of these results suggested that the AgaP1 produced by Paenibacillus sp. K1 was a novel alpha-galactosidase with the highest enzymic activity at low temperature.