An artificial metalloenzyme with the kinetics of native enzymes

P. Dydio,1,2* H. M. Key,1,2* A. Nazarenko,1 J. Y.-E. Rha,1 V. Seyedkazemi,1 D. S. Clark,3,4 J. F. Hartwig1,2† 

Department of Chemistry, University of California, Berkeley, CA 94720, USA. 2Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA. 3Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720, USA. 4Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA. 

28 June 2016; accepted 12 September 2016

 

Science  07 Oct 2016:
Vol. 354, Issue 6308, pp. 102-106
DOI: 10.1126/science.aah4427  

http://science.sciencemag.org/content/sci/354/6308/102.full.pdf

Abstract

Natural enzymes contain highly evolved active sites that lead to fast rates and high selectivities. Although artificial metalloenzymes have been developed that catalyze abiological transformations with high stereoselectivity, the activities of these artificial enzymes are much lower than those of natural enzymes. Here, we report a reconstituted artificial metalloenzyme containing an iridium porphyrin that exhibits kinetic parameters similar to those of natural enzymes. In particular, variants of the P450 enzyme CYP119 containing iridium in place of iron catalyze insertions of carbenes into C–H bonds with up to 98% enantiomeric excess, 35,000 turnovers, and 2550 hours−1 turnover frequency. This activity leads to intramolecular carbene insertions into unactivated C–H bonds and intermolecular carbene insertions into C–H bonds. These results lift the restrictions on merging chemical catalysis and biocatalysis to create highly active, productive, and selective metalloenzymes for abiological reactions.