Bennett R. Streit

Project: The anthropogenic chlorooxides; perchlorate, chlorate, and chlorite, have largely been introduced into the environment within the past 50 years in such products as rocket fuels, herbicides, and paper bleachants. With their powerful oxidizing capabilities these chemicals often act as toxins to most living organisms. Nature however has evolved a set of enzymes to utilize and detoxify itself of these toxins. One of these enzymes is chlorite dismutase (Cld). The recently discovered heme b containing enzyme catalyzes the breakdown of chlorite into O₂ and Cl^-. With this O-O bond forming reaction from chlorite being unique among heme enzymes the questions of how this enzyme works as well as where this enzyme comes from arises. With no sequence homology to any proteins in the NCBI database how this enzyme came about within the past 50 years is a mystery. Also due to the novel type of reaction this enzyme catalyzes, how Cld works is a question we wish to answer. With a through understanding of the kinetics and mechanism of ClO₂^- dismutation it may be possible to understand the nature by which this unique reaction is carried out. An understanding of how the enzyme catalyzes the reaction may allow it to be used in remediation of chlorite contaminated water supplies as well as chlorite sensing applications. Also through an understanding of the reaction, an idea of the possible evolutionally origins of the enzyme may be realized.