MODELING AND KINETICS OF LIGHT-INDUCED PROTON PUMPING OF BACTERIORHODOPSIN RECONSTITUTED LIPOSOMES

Date

1991-09-01

Author

EROGLU, I
ZUBAT, BM
Yücel, Ayşe Meral

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

209
views

0
downloads

Purple membrane fragments isolated from the cell membrane of the photosynthetic bacteria Halobacterium halobium S.9 strain are incorporated into egg yolk phosphatidylcholine liposomes. Purple membrane contains crystalline patches of a retinal protein called bacteriorhodopsin. Upon illumination, bacteriorhodopsin undergoes a reversible photoreaction in which a proton is released on one side of the membrane and a proton is bound on the other side, thus resulting in an electro-chemical gradient across the membrane. The net rate of proton pumping is the combination of the rates of photoreaction and of simple diffusion of protons across the lipid membrane to compensate for the concentration difference between the two sides of the membrane. A mechanistic model is also proposed for the photoreaction which includes activation, proton dissociation, translocation and association reactions. Activation and translocation of bacteriorhodopsin are considered to be fast, but proton dissociation and association steps are considered to be slow. The resultant rate expression is compared with light on and light off experimental data. The model is in accordance with experimental data for initial pH values around 7.

Subject Keywords

Membrane-bound enzymes, Liposomes, Biosynthetic membranes, Biomembrane analogs, Bacteriorhodopsin

URI

https://hdl.handle.net/11511/31043

Journal

JOURNAL OF MEMBRANE SCIENCE

DOI

https://doi.org/10.1016/0376-7388(91)80025-2

Collections

Graduate School of Natural and Applied Sciences, Article

Suggestions

OpenMETU
Core

Modelling of long-term photoresponse of bacteriorhodopsin immobilized on cellulose acetate membranes Sediroglu, V; Aydemir, A; Gündüz, Ufuk; Yucel, M; Turker, L; Eroglu, I (1996-05-01) Purple membrane fragments with its integrated protein bacteriorhodopsin were immobilized on lipid impregnated and lipid free cellulose acetate membranes. Two mathematical models were suggested to simulate the photoresponse curves of these membranes which were obtained by measuring the pH variation independently in each chamber of a specifically designed photoactivity cell for long periods of illumination. The first order model suggested was mainly based on the existence of light phase deprotonation and dark...
Immunomodulatory effects of commensal bacteria-derived membrane vesicles Alpdündar, Esin; Gürsel, Mayda; Department of Biology (2013) Constitutive secretion of extracellular membrane vesicles is a common feature of cells from all domains of life including Archaea, Bacteria, and Eukarya. Although the contribution of gram negative bacterial outer membrane vesicles in disease pathogenesis has been extensively studied, whether commensal bacteria constitutively secrete such vesicles is still unknown. Given the importance of microbiota as regulators of immune homeostasis, we aimed to assess the immunomodulatory properties of extracellular vesic...
Design, synthesis, and characterization of potential self-sorting compounds through differential solvation Tekin, Gizem; Akdağ, Akın; Gökmen, Ali; Department of Chemistry (2016) DNA achieved its double helix form with the help of hydrophilic and hydrophobic interactions. When the sequence of the DNA is examined, it is seen that the DNA bases are the most hydrophobic part, and therefore; they are located at the innermost part of the double helix to avoid interaction with water. This location also enables them to form hydrogen bonds with the complementary DNA base rather than forming them with water. The next part in the sequence is the sugars which have higher solubility in water co...
ANALYSIS OF THE DIELECTROPHORETIC (DEP) SPECTRA OF BIOLOGICAL CELLS Caglayani, Zeynep; Sel, Kaan; Yalcin, Yagmur Demircan; Sukas, Ozlem Sardan; Külah, Haluk (2017-06-22) This study presents an approach for analyzing the dielectrophoretic (DEP) spectra of biological cells without ascertaining their membrane and cytoplasmic properties. DEP spectrum device with reciprocal V-shaped planar-electrodes was utilized to obtain DEP spectra information of cells. Integrating electric field simulations based on a strong theory with the experimental data enables determination of the DEP spectrum at a range of frequencies, for the first in the literature. The proposed method is tested wit...
Comparison of antioxidant enzyme activities and DNA damage in chickpea (Cicer arietinum L.) genotypes exposed to vanadium Imtiaz, Muhammad; Mushtaq, Muhammad Adnan; Rizwan, Muhammad Shahid; Arif, Muhammad Saleem; Yousaf, Balal; Ashraf, Muhammad; Xiong Shuanglian, Xiong Shuanglian; Rizwan, Muhammad; Mehmood, Sajid; Tu, Shuxin (2016-10-01) The present study was done to elucidate the effects of vanadium (V) on photosynthetic pigments, membrane damage, antioxidant enzymes, protein, and deoxyribonucleic acid (DNA) integrity in the following chickpea genotypes: C-44 (tolerant) and Balkasar (sensitive). Changes in these parameters were strikingly dependent on levels of V, at 60 and 120 mg V L-1 induced DNA damage in Balkasar only, while photosynthetic pigments and protein were decreased from 15 to 120 mg V L-1 and membrane was also damaged. It was...

Citation Formats

I. EROGLU, B. ZUBAT, and A. M. Yücel, “MODELING AND KINETICS OF LIGHT-INDUCED PROTON PUMPING OF BACTERIORHODOPSIN RECONSTITUTED LIPOSOMES,” JOURNAL OF MEMBRANE SCIENCE, pp. 325–336, 1991, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/31043.