Analysis of Bacteriorhodopsin Suspended in a Bilayer Lipid Membrane

Abstract

The bacteriorhodopsin protein’s unique characteristic of proton pumping can convert light energy to electric energy. The aim of this research was to generate photocurrent using bacteriorhodopsin in a bi-layer lipid membrane. Lipid monolayer and bilayer were formed using painting and folding methods, respectively. Capacitance and resistance of the lipid membranes were measured and used to validate the best methodology. My results show that the folding method is more efficient in incorporating Bacteriorhodopsin. The photocurrent was generated by illuminating a green laser (532 nm) on the bilayer lipid membranes. The patch clamp electrophysiology technique was used to apply voltage across the lipid membrane and to record photocurrent. For the membrane capacitance and resistance, the ranges were (1.70E-01- 7.50E-01 uF/cm2) and (0.30 - 0.49 GΩ), respectively. The photocurrent density produced was between 5.3 pA/cm2and 7.1 pA/cm2.