title: Cloning, expression, and characterization of a novel (S)-specific alcohol dehydrogenase from Lactobacillus kefir.
abstract: A gene encoding a novel (S)-specific NADH-dependent alcohol dehydrogenase (LK-ADH) was isolated from the genomic DNA of Lactobacillus kefir DSM 20587 by thermal asymmetric interlaced-polymerase chain reaction. The nucleotide sequence of (S)-LK-ADH gene (adhS) was determined, which consists of an open reading frame of 1,044 bp, coding for 347 amino acids with a molecular mass of 37.065 kDa. After a BLAST similarity search in GenBank database, the amino acid sequence of (S)-LK-ADH showed some homologies to several zinc containing medium-chain alcohol dehydrogenases. This novel gene was deposited into GenBank with the accession number of EU877965. adhS gene was subcloned into plasmid pET-28a(+), and recombinant (S)-LK-ADH was successfully expressed in E. coli BL21(DE3) by isopropyl-beta-D-1-thiogalactopyranoside induction. Purified enzyme showed a high enantioselectivity in the reduction of acetophenone to (S)-phenylethanol with an ee value of 99.4%. The substrate specificity and cofactor preference of recombinant (S)-LK-ADH were also tested.
authors.affiliation: State Key Laboratory of New Drug and Pharmaceutical Process, Shanghai Institute of Pharmaceutical Industry, Shanghai, People's Republic of China.
authors.forename: Qilei
authors.initials: Q
authors.lastname: Chen
authors.forename: Youjia
authors.initials: Y
authors.lastname: Hu
authors.forename: Wenjie
authors.initials: W
authors.lastname: Zhao
authors.forename: Chunbao
authors.initials: C
authors.lastname: Zhu
authors.forename: Baoquan
authors.initials: B
authors.lastname: Zhu
mesh_terms: D000426:Alcohol Dehydrogenase / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D003067:Coenzymes / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D007778:Lactobacillus / Q000201:enzymology*; D008969:Molecular Sequence Data; D009243:NAD / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D003067:Coenzymes; D011994:Recombinant Proteins; D009243:NAD; D000426:Alcohol Dehydrogenase