title: 5-fluorotryptophan as dual probe for ground-state heterogeneity and excited-state dynamics in apoflavodoxin.
abstract: The apoflavodoxin protein from Azotobacter vinelandii harboring three tryptophan (Trp) residues, was biosynthetically labeled with 5-fluorotryptophan (5-FTrp). 5-FTrp has the advantage that chemical differences in its microenvironment can be sensitively visualized via (19)F NMR. Moreover, it shows simpler fluorescence decay kinetics. The occurrence of FRET was earlier observed via the fluorescence anisotropy decay of WT apoflavodoxin and the anisotropy decay parameters are in excellent agreement with distances between and relative orientations of all Trp residues. The anisotropy decay in 5-FTrp apoflavodoxin demonstrates that the distances and orientations are identical for this protein. This work demonstrates the added value of replacing Trp by 5-FTrp to study structural features of proteins via (19)F NMR and fluorescence spectroscopy.
authors.affiliation: Microspectroscopy Centre, Wageningen University, Wageningen, The Netherlands.
authors.forename: N V
authors.initials: NV
authors.lastname: Visser
authors.forename: A H
authors.initials: AH
authors.lastname: Westphal
authors.forename: S M
authors.initials: SM
authors.lastname: Nabuurs
authors.forename: A
authors.initials: A
authors.lastname: van Hoek
authors.forename: C P M
authors.initials: CP
authors.lastname: van Mierlo
authors.forename: A J W G
authors.initials: AJ
authors.lastname: Visser
authors.forename: J
authors.initials: J
authors.lastname: Broos
authors.forename: H
authors.initials: H
authors.lastname: van Amerongen
mesh_terms: D001059:Apoproteins / Q000737:chemistry* / Q000235:genetics; D016948:Azotobacter vinelandii / Q000737:chemistry; D005418:Flavodoxin / Q000737:chemistry* / Q000235:genetics; D005454:Fluorescence Polarization / Q000379:methods; D005461:Fluorine / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D019906:Nuclear Magnetic Resonance, Biomolecular; D014364:Tryptophan / Q000031:analogs & derivatives* / Q000737:chemistry / Q000235:genetics
chemical_list: D001059:Apoproteins; D005418:Flavodoxin; C026932:apoflavodoxin; D005461:Fluorine; C026927:5-fluorotryptophan; D014364:Tryptophan