Review - Flavins as photoreceptors of blue light and their spectroscopic properties

Abstract

This review describes 1) the development of studies on flavin photoreceptors as blue light photoreceptors in many living organisms: their kinds and functions; 2) the studies on spectroscopic properties of flavins, both their dimers and monomers; 3) nonradiative excitation energy transport in the presence of monomers and fluorescent/nonflurescent FMN dimers (excitation traps). The existence equilibrated luminescent FMN centers, energy migration and excitation sink to FMN dimers are taken into account.

The Luminescence of 1,8-Diazafluoren-9-One/Titanium Dioxide Composite Thin Films for Optical Application

“…Table 3 presents the results of the mean fluorescence lifetimes of DFO for different concentrations of the dye in the TiO 2 matrix. Shortening of fluorescence lifetime with the increase in the dye concentration evidences the significant presence of aggregates, which can play a double role in the system: firstly, aggregates can act as perfect or imperfect traps for excitation energy transferred from monomers [ 2 , 12 , 34 , 35 , 36 , 37 , 38 , 39 ] and, secondly, the aggregates at highest concentrations are likely to contribute to the fluorescence signal emitting short living fluorescence. A similar behavior has been previously observed and analyzed for several other dyes such as rhodamines and carbocyanines in polymers and hybrid matrices with the only difference that, in this work, the fluorescence spectral shift was found more pronounced, making those analyses more straightforward [ 4 , 39 ].…”

“…The knowledge of whether we are dealing with aggregate or monomer form at a given concentration of the active compound is vital as the actual form may alter the pharmacological activity of the compound as well as its ability to penetrate through biological membranes. Molecular aggregates also play a crucial role as energy transmitters from sunlight in many biological systems [9][10][11][12] and their unusual optical properties are frequently studied and used in various fields of nanoscience and nanotechnology such as efficient energy collecting, spectral broadening of the optical response of fluorescent systems and biosensing on plasmonic platforms [13][14][15]. Although, TiO 2 nano-objects have demonstrated toxicity and ecotoxicity [16][17][18][19], its use in the biomedical devices is widespread and in many cases does not seem to lead to serious side effects.…”

Effects of light quality and nutrient availability on accumulation of mycosporine-like amino acids in Gymnodinium catenatum (Dinophycea)

“…FMN possesses characteristic absorption maxima at 445 nm, 370 nm, 265 nm and 220 nm [18]. Flavin-containing enzymes (flavinproteins) catalyse numerous reactions and in electron transport chains oxidize NADH and NADPH [29].…”

Propensity for Proton Relay and Electrostatic Impact of Protein Reorganization in Slr1694 BLUF Photoreceptor

“…The light-adapted state transmits a long-distance signal to the effector domain, which can be used to control various types of cellular activity. In contrast to other flavin-containing photoreceptors, − the light-adapted state of BLUF is not associated with covalent bonding or redox changes compared to the resting state, but rather is thought to involve reorganization of a hydrogen-bonding network within the active site and possibly protein conformational changes beyond the active site. For the BLUF domain, the spectroscopic signatures of the light-adapted state consist of a 10–15 nm red shift in the flavin absorption spectrum and a 20 cm –1 red shift in the C4O stretch of the flavin. ,− …”