V E Mishiev | PubMed Health

PubMedDate not supplied

[Heterogeneity of phospholipid membranes detected by the fluorescent probe method].

The measurements of fluorescence polarization index within the emission spectra of the fluorescent probes 4-dimethylaminochalcone (DMCh) and 3-methoxybenzantrone (MBA) have indicated that probes are distributed in liposomes prepared from synthetic dipalmitoyl lecithin (DPL) between binding sites of two types. By the method described in the present paper the spectra measured experimentally have been divided into two spectral components. The shape and position of this componential spectra were independent of the probe:lipid concentrations ratio.

Binding Sites↗

PubMedDate not supplied

[Relation between fluorescence and circular dichroism of the complex of the fluorescence probe 4-dimethylaminochalcone with serum albumin].

The fluorescence probe(4-dimethylaminochalcone; DMH) was noncovalently linked to human serum albumin (HSA). The variation of pH was due to serum albumin structural changes, which was determined in terms of DMH and HSA fluorescence and CD spectra. Considerable changes of fluorescence and CD spectra were observed at pH 8 and 10, where there is ionization of two more recently titrated tyrosin residues. It is assumed that these two tyrosine residues are in binding region and quench the fluorescence of DMH between pH 4 to 8. Quenching disappears if these residues are ionized (pH greater than 8) or if the protein undergoes the N -F transition (pH less than 4).

Chalcone↗