A Comparison of Expression and Activity of Heterologous Cytochrome P450 Monoxygenase in Two Yeast Hosts

摘要

Stereo- and regio-specific oxygenation reactions are valuable in the synthesis of fine chemicals. Biocatalytic routes are promising for this class of reactions because they operate under ambient conditions and molecular oxygen is the oxygen source. Furthermore, due to the specificity of enzymes, multiple protection and deprotection steps typical of organic synthesis can be avoided. Cytochrome P450 monooxygenases are a superfamily of enzymes that catalyze an enormous variety of oxygenation reactions. In particular, plant P450s typically have higher substrate specificity than the mammalian enzymes (Chapple, 1998). Currently, efficient systems for enzyme expression and environments that maintain enzymatic activity for prolonged periods are lacking, thus limiting their application. Cinnamate 4-hydroxylase (C4H), a key P450 monooxygenase of the phenylpropanoid pathway in plants, catalyzes the hydroxylation of cinnamic acid. We will present results comparing the expression of C4H in several yeast host strains (Saccharomyces cerevisiae and Schizosaccharomyces pombe). Significant expression levels of enzyme are necessary, but not sufficient for high biocatalytic activity.