Tyrosine 54 and tryptophan 108 of streptavidin are photolabelled by N-(2-nitro-5-azidobenzoyl)-N′-(d-biotinyl)-1,4-diaminobutane and N-(4-azidophenyl)-N′-(d-biotinyl)-1,4-diaminobutane, respectively. Isolation, spectrophotometric characterization and sequence analysis of photolabelled peptides

Photoactivatable Analogues of the Initiating Substrates of RNA Polymerase II Based on Aryl Azide Derivatives of NTP γ-Amidophosphate: Synthesis and Chemical and Photochemical Reactions of Functional Groups

“…An increased acetonitrile concentration necessary to elute the nucleotide derivatives from reversed phase in comparison with ATP indicates the presence of hydrophobic aromatic residues in our products. The 1 H NMR data (see the Experimental section) demonstrate that derivatives ( Ia ) and ( Ib ) contain a p -azidophenyl group ( δ ~ 6.8 and 7 ppm in D 2 O , respectively), whereas ( IIa ) and (IIb) contain 5-azido-2-nitrobenzoyl residue (δ 7.25, 7.28, and 8.2 ppm in D 2 O) [21]. An additional maximum is observed in the electron absorption spectra of compounds (II) (λ max 320 nm); it is close to the absorption maximum of the starting N-(5-azido-2nitrobenzoyl)-1,2-diaminoethane [21].…”

“…The 1 H NMR data (see the Experimental section) demonstrate that derivatives ( Ia ) and ( Ib ) contain a p -azidophenyl group ( δ ~ 6.8 and 7 ppm in D 2 O , respectively), whereas ( IIa ) and (IIb) contain 5-azido-2-nitrobenzoyl residue (δ 7.25, 7.28, and 8.2 ppm in D 2 O) [21]. An additional maximum is observed in the electron absorption spectra of compounds (II) (λ max 320 nm); it is close to the absorption maximum of the starting N-(5-azido-2nitrobenzoyl)-1,2-diaminoethane [21]. The 19 F NMR spectra of (IIIa) and (IIIb) exhibit the signals at δ 13.18 and 22.05 ppm in D 2 O, which are typical of perfluorobenzoyl residue.…”