title: Exceptional thermal stability and organic solvent tolerance of an esterase expressed from a thermophilic host.
abstract: A protein expression system recently developed for the thermophilic crenarchaeon Sulfolobus islandicus was employed to produce recombinant protein for EstA, a thermophilic esterase encoded in the same organism. Large amounts of protein were readily obtained by an affinity protein purification, giving SisEstA. Upon Escherichia coli expression, only the thioredoxin-tagged EstA recombinant protein was soluble. The fusion protein was then purified, and removing the protein tag yielded EcSisEstA. Both forms of the thermophilic EstA enzyme were characterized. We found that SisEstA formed dimer exclusively in solution, whereas EcSisEstA appeared solely as monomer. The former exhibited a stronger resistance to organic solvents than the latter in general, having a much higher temperature optimum (90°C vs. 65°C). More strikingly, SisEstA exhibited a half-life that was more than 32-fold longer than that of EcSisEstA at 90°C. This indicated that thermophilic enzymes yielded from homologous expression should be better biocatalysts than those obtained from mesophilic expression.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
authors.forename: Yuxia
authors.initials: Y
authors.lastname: Mei
authors.forename: Nan
authors.initials: N
authors.lastname: Peng
authors.forename: Shumiao
authors.initials: S
authors.lastname: Zhao
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Hu
authors.forename: Huacai
authors.initials: H
authors.lastname: Wang
authors.forename: Yunxiang
authors.initials: Y
authors.lastname: Liang
authors.forename: Qunxin
authors.initials: Q
authors.lastname: She
mesh_terms: D004791:Enzyme Inhibitors / Q000378:metabolism*; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D004950:Esterases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D007700:Kinetics; D055503:Protein Multimerization; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012997:Solvents / Q000378:metabolism; D013379:Substrate Specificity; D016944:Sulfolobus / Q000201:enzymology* / Q000235:genetics; D013696:Temperature
chemical_list: D004791:Enzyme Inhibitors; D011994:Recombinant Proteins; D012997:Solvents; D004950:Esterases