Transient Transmembrane-Electrostatically Localized Protons and Transmembrane Potential in a Laser Flashed Bacteriorhodopsin Purple Membrane Open Flat Sheet – Summary
James Weifu Lee*
Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA 23529 USA
*Correspondence: jwlee@odu.edu
ORCID: 0000-0003-2525-5870
Keywords: Bacteriorhodopsin purple membrane, liquid water as protonic conductor, transmembrane potential, transmembrane-electrostatically localized protons/cations, bioenergetics
Submitted: September 16, 2024
Revised: July 20, 2025
Accepted: August 26, 2025
Published: September 26, 2025
Abstract
The transmembrane-electrostatically localized protons/cations charges (TELCs, also known as TELPs) model may serve as a unified framework to explain a wide range of bioenergetic phenomena. Transient transmembrane-electrostatically localized protons (TELPs) and transmembrane potential in a laser flash-energized bacteriorhodopsin (bR) purple membrane (PM) open flat sheet are now better analyzed. Under the Heberle et al. (1994) experimental conditions, the number of bR molecules is now calculated to be 8200 per PM open flat sheet with a diameter of 600 nm. With a single-turnover laser flash intensity of 3 mJ/cm2 to photoexcite 10% of the bR molecules, the laser flash-induced peak TELCs density is calculated to be 2900 per µm2 of PM, which translates to a peak transient transmembrane potential of 50 mV. The bR protonic outlet protrudes into the liquid phase outside the putative “potential well/barrier”. The observation is in line with the TELPs model, but does not support the “potential well/barrier” model. The author encourages research on more relevant protonic capacitor cell systems that have transmembrane potential with TELCs comprising excess positive charges at one side and excess anions at the other side of the membrane.