Chlorite dismutase

The chlorite dismutase that generates oxygen from chlorite produced by reduction of chlorate has been purihed and characterized from strain GR-1 (Van Ginkel et al. 1996) and from Ideonella dechloratans (Stenklo et al. 2001). The enzyme from Dechloromonas agitata has been suggested as a metabolic probe for chlorate reduction in the environment (Bender et al. 2002). 

Bender KS, SM O Connor, R Chakraborty, JD Voates, LA Achenbach (2002) Sequencing and transcriptional analysis of the chlorite dismutase gene of Dechloromonas agitata and its use as a metabolic probe. A/ / / Environ Microbiol 68 4820-4826. 

Stenklo K, HD Thorell, H Bergius, R Aasa, T Nilsson (2001) Chlorite dismutase from Ideonella dechloratans. J Biol Inorg Chem 6 601-607. 

Van Ginkel CG, GB Rikken, AGM Kroon, SWM Kengen (1996) Purification and characterization of chlorite dismutase a novel oxygen-generating enzyme. Arc/ Microh/oZ 166 321-326. 

Chlorate has been shown to support the growth of an anaerobic community growing at the expense of acetate (Malmqvist et al. 1991), and a pure culture designated Ideonella dechlorans has been isolated (Malmqvist et al. 1994). A bacterium, strain GR-1 is able to carry out the sequential reduction of perchlorate to chlorate, chlorite, and chloride at the expense of acetate (Rikken et al. 1996), and the chlorite dismutase has been purified and characterized (Van Ginkel et al. 1996). 

Chlorite dismutase (Cld) contains a heme b active site, analogous to peroxidases, and occurs in perchlorate and chlorate respiring bacteria.28 Perchlorate (CIO ) is a rocket fuel and used in pyrotechnics and ammunition. It has been found in soil and ground water only recently.29 Due to its size similarity to iodide, perchlorate inhibits the thyroid gland irreversibly. Microbes have evolved to utilize the oxidizing power of perchlorate. These organisms reduce perchlorate to chlorate and chlorate to chlorite... 

FIGURE 3.9 A biomimetic functional model of chlorite dismutase. 

Peroxidase, Oxidase, and Superoxide Dismutase Horseradish Peroxidase.—Chlorine dioxide, CIO a, is formed by the disproportionation of chlorite ClOa" catalysed by HRP,... 

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