The time-dependent fluorescence Stokes shift and kinetics of emission anisotropy of the 1- phenilnaphthylamine (1-AN) probe in solutions and phospholipid bilayer membranes have been examined using subnanosecond laser fluorimeter. It is shown that the electronic spectra of probe in polar viscous and rigid solutions and in vesicles are inhomogeneously broadened. The obtained results prove the existence of the earlier unknown effect of the wavelength- dependent rotation of a probe in bilayer membranes. This rotation exceeds the equilibrium Brownian one and occurs due to the realization of intermolecular interactions energy excess during the relaxation. The free-energy diagram is presented which makes it possible to interpret the whole set of experimental data. A new method for determination of a probe localization and dielectric constant distribution along the polar region of bilayer membranes is suggested. It is found that the function of the probe molecules distribution along the polar region of membranes is well described by Gaussian.

Date Published: 17 June 1993
PDF: 10 pages
Proc. SPIE 1922, Laser Study of Macroscopic Biosystems, (17 June 1993); doi: 10.1117/12.146202

Published in SPIE Proceedings Vol. 1922:
Laser Study of Macroscopic Biosystems
Jouko E. Korppi-Tommola, Editor(s)