[K-35, a fluorescent probe for albumin study: optical properties].

Fluorescent probe N-(carboxyphenyl)imide of 4-(dimethylamino)naphthalic acid, K-35, is used as an indicator of structural changes of human serum albumin molecules in pathology. The probe occupies albumin binding pockets where the probe environment is of very high polarity; probably, the pocket(s) contains protein polar groups and water molecules. At the same time rather small Stokes shift of K-35 fluorescence spectrum shows that the polar group motion is of one-two order of value lower than mobility of polar molecules in polar fluids.

[Features of the binding of the fluorescent probe K-35 to albumin].

The binding of the fluorescent probe K-35 (CAPIDAB, N-(carboxyphenyl)imide of 4-(dimethylamino)naphthalic acid), which is used as an indicator of albumin structural changes in pathology, to human serum albumin has been studied. Based on the data on the fluorescence decay of the probe, four types of sites of binding of K-35 to albumin have been recoonized, which differ by fluorescence decay time (tau) and binding constants (K). Probe molecules bound to the first type of sites have a decay time close to 8-10 ns; this value corresponds to a high fluorescence quantum yield of about 0.

[Kinetics of rearrangement of solvation sheath of an excited molecule of the fluorescent probe 4"-dimethylaminochalcone].

Processes accompanying the quenching of the fluorescent probe 4"-dimethylaminochalcone by hydroxyl groups of the proton-donor solvent 1-butanol have been studied. The kinetics of the deactivation of the excited state of 4"-dimethylaminochalcone has been monitored from the transition absorption spectra at a time resolution of 50 fs and fluorescence decay at a time resolution of 30 ps. The data obtained allow thinking that the next picture occurs in 1-butanol.