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Updated: Jul 16, 2026

T-wave Ion Mobility-mass Spectrometry: Basic Experimental Procedures for Protein Complex Analysis
Published on: July 31, 2010
Crystal structure of photolysed carbonmonoxy-myoglobin
I Schlichting1, J Berendzen, G N Phillips
1Department of Biophysics, Max Planck Institute for Medical Research, Heidelberg, Germany.
Abstract:
Myoglobin is a globular haem protein that reversibly binds ligands such as O2 and CO. Single photons of visible light can break the covalent bond between CO and the haem iron in carbon-monoxy-myoglobin (MbCO) and thus form an unstable intermediate, Mb*CO, with the CO inside the protein. The ensuing rebinding process has been extensively studied as a model for the interplay of dynamics, structure and function in protein reactions. We have used X-ray crystallography at liquid-helium temperatures to determine the structure of Mb*CO to a resolution of 1.5 A. The photodissociated CO lies on top of the haem pyrrole ring C. Comparison with the CO-bound and unligated myoglobin structures reveals that on photodissociation of the CO, the haem 'domes', the iron moves partially out of the haem plane, the iron-proximal histidine bonds is compressed, the F helix is strained and the distal histidine swings towards the outside of the ligand-binding pocket.
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