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Time‐resolved fluorescence studies of flavodoxin Demonstration of picosecond fluorescence lifetimes of FMN in Desulfovibrio flavodoxins
Author(s) -
Visser Antonie J.W.G.,
van Hoek Arie,
Kulinski Tadeusz,
Le Gall Jean
Publication year - 1987
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(87)80493-3
Subject(s) - flavodoxin , desulfovibrio vulgaris , chemistry , photochemistry , fluorescence , flavin group , desulfovibrio , fluorescence spectroscopy , picosecond , ferredoxin , biochemistry , biology , organic chemistry , enzyme , laser , physics , quantum mechanics , bacteria , sulfate , optics , genetics
Picosecond‐resolved fluorescence spectroscopy on FMN bound in flavodoxin from Desulfovibrio vulgaris and Desulfovibrio gigas revealed fluorescence lifetimes of about 30 ps. The lifetime shortening can be explained by charge transfer interaction in the flavin excited state with aromatic amino acid residues. In addition to the short lifetime component, nanosecond lifetimes were also observed in both flavodoxins. The latter fluorescence lifetime in D. vulgaris flavodoxin (5.6 ns) is even longer than that of free FMN (4.7 ns A fixed lifetime analysis of the results from a diluted D. vulgaris flavodoxin solution yielded the dissociation constant of the FMN‐apoflavodoxin complex: K d = 9.4 ∓ 1.4 nM at 20 °C and pH 7.0.