title: A novel cold-adapted and highly salt-tolerant esterase from Alkalibacterium sp. SL3 from the sediment of a soda lake.
abstract: A novel esterase gene (estSL3) was cloned from the Alkalibacterium sp. SL3, which was isolated from the sediment of soda lake Dabusu. The 636-bp full-length gene encodes a polypeptide of 211 amino acid residues that is closely related with putative GDSL family lipases from Alkalibacterium and Enterococcus. The gene was successfully expressed in E. coli, and the recombinant protein (rEstSL3) was purified to electrophoretic homogeneity and characterized. rEstSL3 exhibited the highest activity towards pNP-acetate and had no activity towards pNP-esters with acyl chains longer than C8. The enzyme was highly cold-adapted, showing an apparent temperature optimum of 30 °C and remaining approximately 70% of the activity at 0 °C. It was active and stable over the pH range from 7 to 10, and highly salt-tolerant up to 5 M NaCl. Moreover, rEstSL3 was strongly resistant to most tested metal ions, chemical reagents, detergents and organic solvents. Amino acid composition analysis indicated that EstSL3 had fewer proline residues, hydrogen bonds and salt bridges than mesophilic and thermophilic counterparts, but more acidic amino acids and less hydrophobic amino acids when compared with other salt-tolerant esterases. The cold active, salt-tolerant and chemical-resistant properties make it a promising enzyme for basic research and industrial applications.
authors.affiliation: College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, P. R. China.|Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou 350002, P.R. China.
authors.forename: Guozeng
authors.initials: G
authors.lastname: Wang
authors.affiliation: College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, P. R. China.
authors.forename: Qiaohuang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, P. R. China.
authors.forename: Xianju
authors.initials: X
authors.lastname: Lin
authors.affiliation: School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Tzi Bun
authors.initials: TB
authors.lastname: Ng
authors.affiliation: College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, P. R. China.
authors.forename: Renxiang
authors.initials: R
authors.lastname: Yan
authors.affiliation: College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, P. R. China.|Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou 350002, P.R. China.
authors.forename: Juan
authors.initials: J
authors.lastname: Lin
authors.affiliation: College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, P. R. China.|Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou 350002, P.R. China.
authors.forename: Xiuyun
authors.initials: X
authors.lastname: Ye
mesh_terms: D000222:Adaptation, Physiological; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D056568:Carnobacteriaceae / Q000201:enzymology*; D003001:Cloning, Molecular; D003080:Cold Temperature; D003902:Detergents / Q000737:chemistry; D004795:Enzyme Stability; D004950:Esterases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D060106:Lakes / Q000382:microbiology; D008670:Metals / Q000737:chemistry; D010802:Phylogeny; D020539:Sequence Analysis, Protein; D012965:Sodium Chloride / Q000737:chemistry; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D003902:Detergents; D008670:Metals; D012965:Sodium Chloride; D004950:Esterases