Premium
Quantitative evaluation of the dynamics of proton transfer from photoactivated bacteriorhodopsin to the bulk
Author(s) -
Nachliel E.,
Gutman M.
Publication year - 1996
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(96)00870-8
Subject(s) - bacteriorhodopsin , proton , chemistry , dynamics (music) , chemical physics , biophysics , computational chemistry , physics , nuclear physics , biochemistry , membrane , biology , acoustics
It has been reported by many research groups that protons released during the photocycle of bacteriorhodopsin are detected by surface bound indicators much faster than by indicators in the bulk. In this study we used numerical simulation of chemical reaction's dynamics for analyzing the delayed appearance of protons in the bulk. The results indicate that the low p K surface groups of the membrane, which form an undilutable concentrated matrix of proton binding sites, retain the protons in this space according to the mass action law. The main sites for proton accumulation are the cluster of carboxylates on the cytoplasmic side of the membrane. The protonation of an indicator in the bulk does not proceed by its reaction with free proton, but rather through self‐diffusion of the indicator to the membrane and abstraction of proton from the protonated surface group. The detailed mechanisms which correspond with these reactions are reported.