title: Purification and characterization of hydrolytic haloalkane dehalogenase from Xanthobacter autotrophicus GJ10.
abstract: A new enzyme, haloalkane dehalogenase, was isolated from the 1,2-dichloroethane-utilizing bacterium Xanthobacter autotrophicus GJ10. The purified enzyme catalyzed the hydrolytic dehalogenation of n-halogenated C1 to C4 alkanes, including chlorinated, brominated, and iodinated compounds. The highest activity was found with 1,2-dichloroethane, 1,3-dichloropropane, and 1,2-dibromoethane. The enzyme followed Michaelis-Menten kinetics, and the Km for 1,2-dichloroethane was 1.1 mM. Maximum activity was found at pH 8.2 and 37 degrees C. Thiol reagents such as p-chloromercuribenzoate and iodoacetamide rapidly inhibited the enzyme. The protein consists of a single polypeptide chain of a molecular weight of 36,000, and its amino acid composition and N-terminal sequence are given.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D006088:Gram-Negative Aerobic Bacteria / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D006867:Hydrolases / Q000302:isolation & purification* / Q000378:metabolism; D007700:Kinetics; D008970:Molecular Weight; D013379:Substrate Specificity
chemical_list: D000596:Amino Acids; D006867:Hydrolases; C046137:haloalkane dehalogenase