ULTRAFAST ROTATION AND TRAPPING OF CARBON-MONOXIDE DISSOCIATED FROM MYOGLOBIN

Citation
Mh. Lim et al., ULTRAFAST ROTATION AND TRAPPING OF CARBON-MONOXIDE DISSOCIATED FROM MYOGLOBIN, Nature structural biology, 4(3), 1997, pp. 209-214
Citations number
41
Categorie Soggetti
Biology,"Cell Biology
Journal title
ISSN journal
10728368
Volume
4
Issue
3
Year of publication
1997
Pages
209 - 214
Database
ISI
SICI code
1072-8368(1997)4:3<209:URATOC>2.0.ZU;2-W
Abstract
The nature of ligand motion within proteins has been investigated by m easuring femtosecond time-resolved infrared (IR) spectra of CO photodi ssociated from the haem of myoglobin. Upon dissociation, the CO rotate s approximately 90 degrees and becomes trapped within a ligand docking site located near the binding site. Two trajectories, distinguished s pectroscopically and kinetically with time constants of 0.20+/-0.05 ps and 0.52+/-0.10 ps, lead to CO located within the docking site with o pposite orientations. The protein reorganizes about the 'docked' CO wi th a time constant of 1.6+/-0.3 ps and quickly establishes an energeti c barrier that inhibits the reverse rebinding process.