title: Photolysis-induced structural changes in single crystals of carbonmonoxy myoglobin at 40 K.
abstract: Myoglobin's reversible binding of oxygen is a model for studies of protein control of ligand binding and discrimination. Protein relaxation and geminate ligand rebinding subsequent to ligand photodissociation have been studied extensively by a variety of techniques. The ps to ns time scales for these processes are still much shorter than the ms time resolution of X-ray diffraction experiments, but it may be possible to trap these intermediates at low temperatures. We report here an X-ray diffraction investigation of structural changes induced by photolysis of carbonmonoxy myoglobin crystals at 40 K. Our results provide a structural basis for the interpretation of ambient and low temperature spectroscopic observations and molecular dynamics simulations of the ligand photodissociation and binding processes in haem proteins.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Chicago, IL 60637, USA.
authors.forename: T Y
authors.initials: TY
authors.lastname: Teng
authors.forename: V
authors.initials: V
authors.lastname: Srajer
authors.forename: K
authors.initials: K
authors.lastname: Moffat
mesh_terms: D000818:Animals; D003080:Cold Temperature; D003196:Computer Graphics; D018360:Crystallography, X-Ray; D005583:Fourier Analysis; D009211:Myoglobin / Q000737:chemistry* / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010782:Photolysis; D011485:Protein Binding; D011487:Protein Conformation; D014907:Whales
chemical_list: D009211:Myoglobin; C018013:carboxymyoglobin; D010100:Oxygen