Insights into the catalytic mechanism of a bacterial hydrolytic dehalogenase that degrades the fungicide chlorothalonil.

ABSTRACT: Chlorothalonil (2,4,5,6-tetrachloroisophtalonitrile; TPN) is one of the most commonly used fungicides in the United States. Given TPN's widespread use, general toxicity, and potential carcinogenicity, its biodegradation has garnered significant attention. Here, we developed a direct spectrophotometric assay for the Zn(II)-dependent, chlorothalonil-hydrolyzing dehalogenase from Pseudomonas sp. CTN-3 (Chd), enabling determination of its metal-binding properties; pH dependence of the kinetic parameters k_cat, K_m , and k_cat/K_m ; and solvent isotope effects. We found that a single Zn(II) ion binds a Chd monomer with a K_d of 0.17 μm, consistent with inductively coupled plasma MS data for the as

SUBMITTER: Yang X 

PROVIDER: S-EPMC6737215 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature