Synthesis and characterization of the fluorescence utility of two Visible-Light-Absorbing tryptophan derivatives

Synthesis and Fluorescence Properties of 4-Cyano and 4-Formyl Melatonin as Putative Melatoninergic Ligands

“…The atypical (related to metabolite serotonin in 5-HT receptors) entry mechanism could impose constraints on physicochemical properties (i.e., permanent dipole moment) and can be exploited in the future development of novel fluorescent melatonin-based structures to address the need for better binding. Specifically, we imagine that 4-dicyanovinylmelatonin would be a visible chromophore based on the fact that the 2,2-dicyanovinyl group is a stronger electronic withdrawing group than that of nitrile or formyl as well documented in the literature . In addition, 4CHO-MLT via its aldehydic formyl group could both complement and expand other modes of reactivity (e.g., oxime, hydrazone, and nitrone formation) to probe unusual and novel fluorescent behavior.…”

Unnatural Amino Acids for Biological Spectroscopy and Microscopy

“…397 nm in water, it is essentially nonfluorescent; however, it can be used as an efficient FRET quencher to 4CN-Trp fluorescence with a Förster distance of ca. 35 Å that can be used, for example, to monitor the proteolytic activity of proteolytic enzymes (e.g., trypsin) (Figure ); (3) 4DCV-Trp is a true visible-light-absorbing fluorescent UAA as its λ ab and λ em are at ca. 426 and 580 nm, respectively, in water (Figure ); and (4) the frequency of 4DCV-Trp’s fluorescence maximum exhibits a linear correlation with the solvent polarity index, suggesting that it could serve as a polarity reporter of proteins.…”

“…Also shown in (B) is the schematics of the Lys-Peptide. Reproduced with permission from ref . Copyright 2022 Elsevier B.V.…”

Applications of fluorescence spectroscopy in protein conformational changes and intermolecular contacts

“…Fluorescent microscopy makes use of fluorescent proteins (FPs) [60] , [61] , [62] , [63] , [64] , [65] , [66] , [67] , [68] , [69] , [70] , [71] , [72] , [73] , [74] , [75] , [76] , [77] , [78] , [79] , [80] , [81] , [82] , [83] , [84] , [85] , [86] , [87] , [88] , [89] , [90] , [91] , [92] , [93] , [94] , [95] , [96] , [97] , [98] , [99] , [100] , [101] , [102] , [103] to label target proteins and monitor their localisation in cells, for example, and reveal information about the target protein's relationships with other molecules within cells. It has become an essential tool in biology and the biomedical sciences.…”