title: The effect of point mutation on the equilibrium structural fluctuations of ferric Myoglobin.
abstract: The ultrafast equilibrium fluctuations of the Fe(III)-NO complex of a single point mutation of Myoglobin (H64Q) have been studied using Fourier Transform 2D-IR spectroscopy. Comparison with data from wild type Myoglobin (wt-Mb) shows the presence of two conformational substates of the mutant haem pocket where only one exists in the wild type form. One of the substates of the mutant exhibits an almost identical NO stretching frequency and spectral diffusion dynamics to wt-Mb while the other is distinctly different in both respects. The remarkably contrasting dynamics are largely attributable to interactions between the NO ligand and a nearby distal side chain which provides a basis for understanding the roles of these side chains in other ferric haem proteins.
authors.affiliation: Department of Physics, University of Strathclyde, Glasgow, Scotland, UK. katrin.adamczyk@strath.ac.uk
authors.forename: Katrin
authors.initials: K
authors.lastname: Adamczyk
authors.forename: Marco
authors.initials: M
authors.lastname: Candelaresi
authors.forename: Rafal
authors.initials: R
authors.lastname: Kania
authors.forename: Kirsty
authors.initials: K
authors.lastname: Robb
authors.forename: Cesar
authors.initials: C
authors.lastname: Bellota-Antón
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Greetham
authors.forename: Mark R
authors.initials: MR
authors.lastname: Pollard
authors.forename: Michael
authors.initials: M
authors.lastname: Towrie
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Parker
authors.forename: Paul A
authors.initials: PA
authors.lastname: Hoskisson
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Tucker
authors.forename: Neil T
authors.initials: NT
authors.lastname: Hunt
mesh_terms: D000818:Animals; D005290:Ferric Compounds / Q000737:chemistry; D006736:Horses; D008958:Models, Molecular; D009211:Myoglobin / Q000737:chemistry* / Q000235:genetics*; D009569:Nitric Oxide / Q000737:chemistry; D017354:Point Mutation; D011487:Protein Conformation; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D005290:Ferric Compounds; D009211:Myoglobin; D009569:Nitric Oxide