Cloning and Characterization of an Enantioselective l-Menthyl Benzoate Hydrolase from Acinetobacter sp. ECU2040.
A new esterase gene abmbh, encoding a benzoate hydrolase which can enantioselectively hydrolyze l-menthyl benzoate to l-menthol, was recently identified from the genomic library of a soil isolate Acinetobacter sp. ECU2040. The abmbh gene contains a 1080-bp open reading frame encoding a protein of 360 amino acids with a calculated molecular mass of 40.7 kDa. The corresponding enzyme AbMBH was functionally expressed in Escherichia coli BL21 (DE3), purified, and characterized. The AbMBH displayed the maximum activity towards p-nitrophenyl butyrate at 50 °C, and an optimum pH of 8.5. A K M of 2.6 mM and a k cat of 0.26 s(-1) were observed towards dl-menthyl benzoate. The AbMBH exhibited a moderate enantioselectivity (E = 27.5) towards dl-menthyl benzoate. It can also catalyze the enantioselective hydrolysis of a variety of racemic menthyl esters, including dl-menthyl acetate, dl-menthyl chloroacetate, and dl-menthyl butyrate.
Laboratory of Biocatalysis and Synthetic Biotechnology, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.
Jin-Gang
JG
Yin
Guo-Chao
GC
Xu
Gao-Wei
GW
Zheng
Jian-He
JH
Xu
D000150:Acinetobacter / Q000737:chemistry* / Q000201:enzymology; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D001565:Benzoates / Q000737:chemistry*; D002087:Butyrates / Q000737:chemistry; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D004950:Esterases / Q000737:chemistry* / Q000235:genetics; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008610:Menthol / Q000737:chemistry*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016366:Open Reading Frames; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment; D013237:Stereoisomerism; D013379:Substrate Specificity
D001426:Bacterial Proteins; D001565:Benzoates; D002087:Butyrates; D011994:Recombinant Proteins; D008610:Menthol; C033592:4-nitrophenyl butyrate; D004950:Esterases