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

FEBS Letters

Büldt, Georg²  Möckel, Bettina²  Bamberg, Ernst¹  Nagel, Georg¹ 

[1] Max-Planck-Institut für Biophysik, Kennedy-Allee 70, D-60596 Frankfurt, Germany;IBI-2, Forschungszentrum Jülich, D-52425 Jülich, Germany

关键词: Bacteriorhodopsin;    H+-pump;    Voltage dependence;    Xenopus oocyte;    BLM;    black lipid membrane;    BR;    bacteriorhodopsin;    bop;    bacterio-opsin;    EGTA;    ethylene glycol-bis(β-aminoethyl ether) N;    N;    N′;    N′-tetraacetic acid;    HEPES;    N-[2-hydroxyethyl]piperazine-N′-[2-ethanesulfo nic acid];    MOPS;    3-[N-morpholino]propanesulfonic acid;    NMG;    TEA;    tetraethylammonium;    V h;    holding potential;   

DOI  :  10.1016/0014-5793(95)01356-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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 μm² 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.

【 授权许可】

Unknown