ENVR 147 |
| Phenolic chemicals present in drinking water may elicit physiological responses similar to endogenous estrogen even at very low concentrations. Many of these chemicals are also substrates of the enzyme horseradish peroxidase (HRP). Unfortunately, smaller more weakly estrogenic substrates are more efficiently degraded than larger, more potent estrogens (i.e., 17β-estradiol). Because differential HRP activity has been attributed to poor enzyme-substrate binding, as parameterized using a quantitative structure activity relationship (QSAR), six previously-documented HRP mutants were investigated in a computational study of enzyme-substrate binding. Resulting simulation-predicted binding distances correlate with literature rates of reaction between mutants and test substrate, 2-methoxyphenol. This correlation (R2 = 0.86) bears out a hypothesis, based on the QSAR, that reduction in binding distance between HRP and any selected substrate mediates increased HRP reactivity towards that substrate. In a larger sense, results validate use of QSARs as means to formulate mutations designed to enhance reactivity towards priority pollutants. |
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Advances in Abiotic Transformation Processes for Micropollutants in Drinking Water and for Sourcewater Protection
1:30 PM-5:10 PM, Tuesday, April 8, 2008 Morial Convention Center -- Rm. 237, Oral
Division of Environmental Chemistry |