Synthesis and Spectral Characterization of Sulfhydryl-Reactive Fluorescent Probes

A non‐natural amino acid for efficient incorporation into proteins as a sensitive fluorescent probe

“…The peak position shifted to shorter wavelengths continuously from 0% ethanol (415 nm) to 100% ethanol (403 nm). A similar tendency has been reported previously [12]. Thus, the blue shift of the fluorescence of the 120atnDap mutant from 416 nm to 401 nm by biotin binding may be reasonably interpreted in terms of the relocation of the anthraniloyl chromophore from the hydrophilic region to a hydrophobic region.…”

“…To this aim, we designed two fluorescent amino acids that contain anthraniloyl groups. The anthraniloyl group is a small fluorescent chromophore compared to most of the fluorophores commonly used for protein labeling [11,12] and will give rise to minimum conformational perturbations when they are incorporated into proteins. Moreover, the anthraniloyl group emits fluorescence at wavelengths longer than 400 nm and can be detected without interference from the intrinsic tryptophan fluorescence.…”

Synthesis and characterization of a novel reagent containing dansyl group, which specifically alkylates sulfhydryl group: An example of application for protein chemistry

“…It includes N-(2-bromoacethylamino)ethyl-2-(methylamino)benzamide (Br-MANT) [1], deamino lysine(N 6 -N-maleoyl-h-alanine)-8-arginine vasopressin (d[Lys 8 ]VP) [2], 3-(2-pyridyldithio)propionylarginyl-[ 125 I]-monoiodotyrosine (TP-Arg-ITyr) [3], N-(4-azidophenylthio)phthalimide (APTP) [4], monobromobimane (mBBr) [5], N-(iodoacethylaminoethyl)-naphthylamine-sulfonic acid (I-AEDANS) [6] and N-( p-(2-benzoxazoyl)phenyl) maleimide (BIPM) [7]. Using these reagents, sulfhydryl groups in proteins and small molecules had been detected by its fluorescence (Br-MANT, mBBr, I-AEDANS, BIPM), radioactivity (d[Lys 8 ]VP, TP-Arg-ITyr) or ultraviolet absorption (APTP).…”

A small fluorophore reporter of protein conformation and redox state

“…This probe and its N-methyl derivative are popular for labeling of nucleotides 6 and peptides 7,8 but in the absence of efficient labeling reagents their applications to proteins so far have been rare and rather specialized. 9,10 Two N-methyl anthraniloyl-derived thiol-labeling reagents (N-[2-[(bromoacetyl)amino]ethyl]-2-(methylamino)benzamide 10 and 2-[(iodoacetyl)-methyl-amino]-6-(methylamino)benzoic acid methyl ester) 11 have been reported but they have not found widespread use in protein chemistry possibly owing to thermal degradation 10 and limited solubility in aqueous solutions. Analysis of their structures and reported properties, as well as our previous work with dye-labeled proteins, 4 suggested that an additional ionizable group at the aromatic ring could not only improve the reagent's solubility in aqueous solutions but also allow for easy chromatographic separation of labeled and unlabeled proteins.…”

“…Such a solvent dependence and two-component decay in aqueous solutions have been previously reported for other anthraniloyl probes. 10 We have labeled with Atpt cysteine mutants of two representative proteins, a positively charged heme protein cytochrome c (cyt c, Fig. 1), 12 and a negatively charged D1 domain of cytoskeletal protein vinculin (Fig.…”