Purification and Properties of Haloacetate Halidohydrolase Specified by Plasmid fromMoraxellasp. Strain B

Abstract

Haloacetate halidohydrolase II specified by a plasmid pUOI was purified from haloacetateassimilating Moraxella sp. B. The purification procedures included protamine treatment, ammonium sulfate fractionation, and column chromatographies with DEAE-cellulose, hydroxyapatite and Bio-gel P-150, resulting in a 200-fold purification. The purified enzyme was homogeneous by criteria of ultracentrifugation and disc electrophoresis. The molecular weight estimated by Sephadex G-I00 gel filtration was 43,000, and it was 26,000 by SDS-polyacrylamide gel electrophoresis. The sedimentation coefficient sgo,w was 4.1 S, and the isoelectric point was pH 5.2. The amino acid composition was also estimated. The enzyme catalyzed the dehalogenation of monochloro-, mono bromo-and monoiodoacetate, but not monofiuoroacetate. 2,2-Dichloroacetate and 2-chloropropionate were slightly dehalogenated, but trichloroacetate and 3-chloropropionate were not. The enzyme was very sensitive to inhibition with thiol reagents.

Crystal Structure of L-2-Haloacid Dehalogenase from Pseudomonas sp. YL

“…L-DEXs are very similar to one another in their primary structures (8), and also to haloacetate dehalogenase H-II from Moraxella sp. (9).…”

Biosynthesis of fatty acids and related metabolites

“…94 Bacteria or fungi that can utilise fluoroacetate as a source of acetate contain enzymes that convert fluoroacetate to hydroxyacetate. 95 Harper and co-workers have examined the biosynthesis of fluoroacetate and 4-fluorothreonine by S. cattleya NRRL 8057, and suggest that hydroxyacetate is the precursor of fluoroacetate. 96…”

Purification and Properties of 2-Halo Acid Dehalogenase fromPseudomonas putida

“…3 • 4 ) However, little attention has been paid to 2-halo acid dehalogenase, particularly its enzymological aspects. We here report the purification of 2-halo acid dehalogenase from Pseudomonas putida and its characterization.…”