Functional expression of bacteriorhodopsin in oocytes allows direct measurement of voltage dependence of light induced H+ pumping

FEBS Lett. 1995 Dec 18;377(2):263-6. doi: 10.1016/0014-5793(95)01356-3.


We report on the first successful expression of the light driven H+ pump, bacteriorhodopsin, into the plasma membrane of oocytes from Xenopus laevis. The light induced photocurrents which reflect the pumping of H+ by BR were analysed under voltage clamp conditions. At least 100 active BR molecules per microns 2 were expressed in the plasma membrane so that both the voltage clamp and giant patch clamp method could be applied. We show that H+ pumping by BR is modulated by the membrane potential, i.e. the pump current shows strong voltage dependence in the range measured between -165 mV to +60 mV.

MeSH terms

  • Animals
  • Bacteriorhodopsins / chemistry
  • Bacteriorhodopsins / genetics*
  • Electrochemistry
  • Light
  • Membrane Potentials
  • Oocytes
  • Patch-Clamp Techniques
  • Proton Pumps / chemistry
  • Proton Pumps / genetics*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Retinaldehyde / metabolism
  • Xenopus laevis


  • Proton Pumps
  • Recombinant Proteins
  • Bacteriorhodopsins
  • Retinaldehyde