Substrate SARs in human P450s.

Drug metabolism is now an integral part of the drug discovery process, and the cytochromes P450 (CYPs) are the most important family of enzymes involved in human drug metabolism. An increased understanding of the properties of the substrates for the major human CYPs is thus highly desirable. This article shows how key characteristics of CYP substrates, such as lipophilicity, molecular mass and hydrogen-bonding potential, govern selectivity towards individual CYPs. Importantly, the variation in binding affinities of 60 human CYP substrates can be explained by understanding the key physicochemical, structural and electronic characteristics that govern substrate binding to each isozyme.