Converting Phenylacetone Monooxygenase into Phenylcyclohexanone Monooxygenase by Rational Design:Towards Practical Baeyer-Villiger Monooxygenases

A homology model of the most frequently used, but thermally somewhat labile, Baeyer–Villiger monooxygenase, cyclohexanone monooxygenase (CHMO) has been derived on the basis of the recently published crystal structure of the thermally stable phenylacetone monooxygenase (PAMO). This has led to the identification of a structural element crucial for substrate acceptance and stereoselectivity, namely an arginine-interacting loop near the active site. A bulge in this loop occurring in PAMO (but not in CHMO) has been eliminated by mutation, enhancing the range of substrate acceptance and enantioselectivity of Baeyer–Villiger reactions while maintaining high thermal stability