title: Expression of a β-mannosidase from Paenibacillus polymyxa A-8 in Escherichia coli and characterization of the recombinant enzyme.
abstract: Paenibacillus polymyxa A-8, which secretes β-mannosidase, was isolated from the soil sample under a pine tree located in the "Laoban" mountain region of Sichuan, China. The β-mannosidase gene (MANB) was isolated from P. polymyxa A-8, using primers according to the complete genome. The MANB (2,550 bp) encoding 849 amino acid residues was expressed in Escherichia coli. The specific activities of β-mannosidase produced by P. polymyxa A-8 and E. coli pET30a-MANB were 12 nkat/mg and 635 nkat/mg respectively. SDS-PAGE analysis indicated that the molecular mass of the recombinant MANB was approximately 96 kDa. The recombinant MANB was active between pH 7.0-8.5 with the maximum activity at pH 7.0. It had good pH stability and adaptability. The MANB had the optimal temperature of 35°C and was relatively stable at 35-40°C. In addition, the MANB activity was enhanced by K+, Ca2+, Mn2+, and Mg2+ and inhibited by Zn2+, Cu2+, and Hg2+.
authors.affiliation: College of Science, Sichuan Agricultural University, Yaan, Sichuan 625000, P. R. China.
authors.forename: Xi
authors.initials: X
authors.lastname: Bai
authors.affiliation: College of Science, Sichuan Agricultural University, Yaan, Sichuan 625000, P. R. China; College of Animal Science, Anhui Science and Technology University, Fengyang, Anhui 233100, P. R. China.
authors.forename: Hong
authors.initials: H
authors.lastname: Hu
authors.affiliation: College of Science, Sichuan Agricultural University, Yaan, Sichuan 625000, P. R. China.
authors.forename: Huaping
authors.initials: H
authors.lastname: Chen
authors.affiliation: College of Science, Sichuan Agricultural University, Yaan, Sichuan 625000, P. R. China.
authors.forename: Quanbin
authors.initials: Q
authors.lastname: Wei
authors.affiliation: Liang Shan Zhong Ze New Technology Development Co., Ltd, Xichang, Sichuan 615000, P. R. China.
authors.forename: Zeshen
authors.initials: Z
authors.lastname: Yang
authors.affiliation: College of Science, Sichuan Agricultural University, Yaan, Sichuan 625000, P. R. China.
authors.forename: Qianming
authors.initials: Q
authors.lastname: Huang
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D056507:Paenibacillus / Q000201:enzymology* / Q000235:genetics; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D044902:beta-Mannosidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D044902:beta-Mannosidase