Colorimetric Screen for Aliphatic Hydroxylation by Cytochrome P450 Using p-Nitrophenyl-Substituted Alkanes

The United States consumes approximately 16–17 million barrels of crude oil per day, and the majority is used for electricity, heating, and transportation fuel (1 ). The main constituents of crude oil are linear aliphatics. Clearly, the selective hydroxylation of alkanes to more valuable products would have a worldwide economic impact. Unfortunately, the chemical methods for the oxidation of alkanes are energy intensive, and the reagents and byproducts are hazardous to the environment (2 ). In order to overcome these shortcomings, biocatalysts such as heme (3 ) and non-heme monooxygenases (4 ) offer an attractive alternative to alkane oxidation. However, the known alkane hydroxylases are sluggish (∼1–200 min⁻¹ ), and high-throughput screens for aliphatic hydroxylation are expected to be useful in discovering more active clones from enzyme libraries.