Human carbonic anhydrase II as host protein for the creation of artificial metalloenzymes: the asymmetric transfer hydrogenation of imines

In the presence of human carbonic anhydrase II, aryl-sulfonamide-bearing IrCp* pianostool complexes catalyze the asymmetric transfer hydrogenation of imines. Critical cofactor-protein interactions revealed by the X-ray structure of [(eta(5)-Cp*)Ir(pico 4)CI] 9 subset of WT hCA II were genetically optimized to improve the catalytic performance of the artificial metalloenzyme (68% ee, k(cat)/K-M 6.11 x 10(-3) min(-1) mM(-1)).