title: The electronic structure of the neutral isoalloxazine semiquinone within Anabaena flavodoxin: new insights from HYSCORE experiments.
abstract: A complete study of Anabaena flavodoxin in the neutral semiquinone state by means of the EPR pulse technique HYSCORE is here presented. The results provide new information about the hyperfine interactions of the unpaired electronic spin and the nuclei in the isoalloxazine ring. This allows a better knowledge of the electronic structure of the neutral flavin radical within the protein. Combination of these results with other previously obtained by using other EPR related techniques allowed producing a very precise mapping of the flavin spin distribution in the neutral semiquinone state. This information can be very useful for determining the relationship between the electronic structure and mechanisms in flavoproteins. An experimental protocol for measuring the electronic structure details available to date is suggested.
authors.affiliation: Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-Consejo Superior de Investigaciones Científicas, Facultad de Ciencias, C/Pedro Cerbuna 12, 50009 Zaragoza, Spain. jimartin@unizar.es
authors.forename: Jesús I
authors.initials: JI
authors.lastname: Martínez
authors.forename: Pablo J
authors.initials: PJ
authors.lastname: Alonso
authors.forename: Milagros
authors.initials: M
authors.lastname: Medina
mesh_terms: D017033:Anabaena / Q000737:chemistry*; D016880:Anisotropy; D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport; D005415:Flavins / Q000737:chemistry*; D005418:Flavodoxin / Q000737:chemistry*; D005420:Flavoproteins / Q000737:chemistry; D007536:Isomerism; D008872:Microwaves; D011809:Quinones / Q000737:chemistry
chemical_list: D005415:Flavins; D005418:Flavodoxin; D005420:Flavoproteins; D011809:Quinones; C001922:lumiflavin; C008173:isoalloxazine