Electrochemical biosensors that combine high selectivity of biochemical affinity with precise electrochemical detection are one the most necessary and powerful tools for assessing environmental pollution. This review addresses assess pollutant toxicity. using enzyme activity inhibition, DNA, whole cells, cytochrome P450 will be introduced, their advantages applications discussed, trends challen...

A unique metabolite with a molecular mass of 119 Da (C(2)H(5)N(3)O(3)) accumulated during biotransformation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by Rhodococcus sp. strain DN22 (D. Fournier, A. Halasz, J. C. Spain, P. Fiurasek, and J. Hawari, Appl. Environ. Microbiol. 68:166-172, 2002). The structure of the molecule and the reactions that led to its synthesis were not known. In the p...

We are constantly exposed to many potentially toxic chemicals. Most require metabolic activation to species responsible for cell injury. Although cytochrome P450 2E1 is only one of many different forms of cytochrome P450 that catalyze these reactions, it has an important role in human health as a result of being readily induced by acute and chronic alcohol ingestion. The enzyme efficiently cata...

The initial view that the cytochrome P450 enzyme system functions simply in the deactivation of xenobiotics is anachronistic on the face of mounting evidence that this system can also transform many innocuous chemicals to toxic products. However, not all xenobiotic-metabolising cytochrome P450 subfamilies show the same propensity in the bioactivation of chemicals. For example, the CYP2C, 2B and...

When the cDNA encoding bovine microsomal 17 alpha-hydroxylase cytochrome P450 (P45017 alpha) containing modifications within the first seven codons which favor expression in Escherichia coli is placed in a highly regulated tac promoter expression plasmid, as much as 16 mg of spectrally detectable P45017 alpha per liter of culture can be synthesized and integrated into E. coli membranes. The kno...

A functional human NADH-dependent cytochrome P450 system has been developed by altering the cofactor preference of human NADPH cytochrome P450 reductase (CPR), the redox partner for P450s. This has been achieved by a single amino acid change of the conserved aromatic amino acid Trp-676, which covers the re-side of the FAD isoalloxazine ring in the nicotinamide-binding site. Of the mutations mad...

Human cytochromes P450 2S1 and 2W1 have received only limited attention with regard to characterization of function. Both cytochromes P450 have been reported to be overexpressed in human tumors, and cytochrome P450 2S1 is induced by carcinogenic polycyclic hydrocarbons. We report methods for high-level expression and purification of both cytochromes P450 from Escherichia coli, with the goal of ...