Phase one reactions involve the addition or unmasking of a functional polar group, typically resulting in a relatively small increase in hydrophilicity. The CYP450 mixed function oxidases are microsomal enzymes that collectively are the most catalytically versatile and important phases one enzymes. The human genome encodes 60 distinct CYP450 genes that are grouped based on similarities in the amino acid sequences of these enzymes into 18 gene families that are divided into 42 subfamilies. The relative importance of the various members of CYP families 1-3 in human xenobiotic metabolism is represented in the figure below.

Phase two reactions involve the conjugation of xenobiotics to a small hydrophilic endogenous substance (e.g. glutathione, glucuronic acid, or cysteine) to render it more hydrophilic, facilitating excretion. We offer an extensive and rowing line of antibodies to characterize phases two enzymes as well as an array of purified, recombinant, active proteins for in vivo studies.