Purification and crystallization of N-terminally truncated forms of microsomal cytochrome P450 2C5

Engineering more soluble forms of P450 2C5 has contributed to the crystallization of the enzyme. When detergents are used in both crystallization and purification of the protein, the ability to control the content and identity of the detergent is dependent on the protein exhibiting a sufficient degree of solubility to permit its concentration in the absence of detergents. The production of concentrated solutions of the protein containing little or no detergent provides a means for screening crystallization conditions and the selection of detergents that facilitate crystallization. These detergents can then be used not only to improve the purification of the protein, but also to solublize substrates for the cocrystallization of enzyme-substrate complexes.