Alternative modes of O₂ activation in P450 and NOS enzymes are clarified by DFT modeling and resonance Raman spectroscopy.

ABSTRACT: The functions of heme proteins are modulated by hydrogen bonds (H-bonds) directed at the heme-bound ligands by protein residues. When the gaseous ligands CO, NO, or O₂ are bound, their activity is strongly influenced by H-bonds to their atoms. These H-bonds produce characteristic changes in the vibrational frequencies of the heme adduct, which can be monitored by resonance Raman spectroscopy and interpreted with density functional theory (DFT) computations. When the protein employs a cysteinate proximal ligand, bound O₂ becomes particularly reactive, the course of the reaction being controlled by H-bonding and proton delivery. In this work, DFT modeling is used to examine the effects of H-bonding to either the terminal (O^t) or proximate (O^p) atom

SUBMITTER: Soldatova AV 

PROVIDER: S-EPMC7247924 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature