抄録
The binding mechanism of 1-anilino-8-naphthalenesulfonate (ANS), called “hydrophobic probe, ” to polyvinylpyrrolidone (PVP), poly-N-vinyl-2-oxazolidone (PVO), poly-N-vinyl-5-methyl-2-oxazolidone (PVMO) and polyethylene glycol-20M (PEG-20M) was investigated as an approach to understanding of the interaction between ANS and biological components.
A high fluorescence emission was observed when the above synthetic water soluble polymers were added to aqueous solution of ANS. The emission maximum appeared at 480 mμ by the excitation at 365 mμ in the cases of PVP K-15, PVP K-30, PVO and PVMO, and at 475 mμ in the case of PEG-20M. The fluorescence was polarized in ANS/PVP/water, as was described with Perrin's equation. The enhancement and the shift of fluorescence emission were not observed in ANS/polyethylene imine/water.
The shift of signals to higher field on the proton magnetic resonance spectra of the model systems ANS/N-methyl-2-pyrrolidone/D2O and ANS/N-chloroethyl-2-oxazolidone/D2O suggested that ANS may stack on pyrrolidone and oxazolidone rings, respectively.
PEG-20M gave a ultraviolet absorption spectrum and another infrared absorption around 1515 cm1 than PEG 4000 and 6000 did and also gave two peaks on the gel permeation chromatogram. The fluorescence intensity at 310 mμ, excited at 265 mμ, decreased with the increase of concentration of ANS. Accordingly, it was considered possiblethat some aromatic residue was incorporated in the PEG-20M molecule as have been reported in some other cases and this residue played an important role in the binding of ANS to PEG-20M.
