title: A mono-2-ethylhexyl phthalate hydrolase from a Gordonia sp. that is able to dissimilate di-2-ethylhexyl phthalate.
abstract: Gordonia sp. strain P8219, a strain able to decompose di-2-ethylhexyl phthalate, was isolated from machine oil-contaminated soil. Mono-2-ethylhexyl phthalate hydrolase was purified from cell extracts of this strain. This enzyme was a 32,164-Da homodimeric protein, and it effectively hydrolyzed monophthalate esters, such as monoethyl, monobutyl, monohexyl, and mono-2-ethylhexyl phthalate. The K(m) and V(max) values for mono-2-ethylhexyl phthalate were 26.9 +/- 4.3 microM and 18.1 +/- 0.9 micromol/min . mg protein, respectively. The deduced amino acid sequence of the enzyme exhibited less than 30% homology with those of meta-cleavage hydrolases which are serine hydrolases but exhibited no significant homology with the sequences of serine esterases. The pentapeptide motif GXSXG, which is conserved in serine hydrolases, was present in the sequence. The enzymatic properties and features of the primary structure suggested that this enzyme is a novel enzyme belonging to an independent group of serine hydrolases.
authors.affiliation: Department of Applied Life Science, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082, Japan.
authors.forename: Tuguhiro
authors.initials: T
authors.lastname: Nishioka
authors.forename: Makoto
authors.initials: M
authors.lastname: Iwata
authors.forename: Takuya
authors.initials: T
authors.lastname: Imaoka
authors.forename: Maiko
authors.initials: M
authors.lastname: Mutoh
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Egashira
authors.forename: Takashi
authors.initials: T
authors.lastname: Nishiyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Shin
authors.forename: Takao
authors.initials: T
authors.lastname: Fujii
mesh_terms: D004051:Diethylhexyl Phthalate / Q000031:analogs & derivatives* / Q000378:metabolism*; D033601:Gordonia Bacterium / Q000201:enzymology*; D006867:Hydrolases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA
chemical_list: D004051:Diethylhexyl Phthalate; D006867:Hydrolases; C016599:mono-(2-ethylhexyl)phthalate