Disentangling ligand migration and heme pocket relaxation in cytochrome P450cam.

ABSTRACT: In this work we show that ligand migration and active site conformational relaxation can occur independently of each other in hemoproteins. The complicated kinetics of carbon monoxide rebinding with cytochrome P450cam display up to five distinct processes between 77 K and 300 K. They were disentangled by using a combination of three approaches: 1), the competition of the ligand with xenon for the occupation of internal protein cavities; 2), the modulation of the amount of distal steric hindrance within the heme pocket by varying the nature of the substrate; and 3), molecular mechanics calculations to support the proposed heme-substrate relaxation mechanism and to seek internal cavities. In cytochrome P450cam, active site conformational relaxation results from the displacement of the substr

SUBMITTER: Tetreau C 

PROVIDER: S-EPMC1305127 | biostudies-literature | 2005 Feb

REPOSITORIES: biostudies-literature