Characteristics and the
Mechanism of Bacteriorhodopsin Photoelectric Response
YAO Bao-Li*, WANG Ying-Li, HU Kun-Sheng1,
CHEN De-Liang1, ZHENG Yuan, LEI Ming
( State Key Laboratory of Transient Optics Technology, Xi’an Institute of
Optics and Precision Mechanics, the Chinese Academy of Sciences, Xi’an 710068,
China；1Institute of Biophysics, the Chinese
Academy of Sciences, Beijing 100101, China )
Abstract Oriented
bacteriorhodopsin films were prepared on ITO conductive glass by using
electrophoretic or Langmuir-Blodgett methods to construct photocells.Pulse
response photovoltages under stimulation of pulsed laser and
differentialresponse signals under irradiation of discontinued light were
respectively measured, and the origins of the two responses and their
correlation are analyzed. The pulse response photovoltage initiated from the
ultrafast charge separation of the retinal and the proton translocation, followed
by the deprotonation and reprotonation of the Schiff base and its surrounding
amino acids. This was a quick response and was the preceding reaction of the
differential response. The differential response was caused by the charging and
discharging of the continuous proton current of the BR light-driven proton pump
at the light-on and light-off, as well as the coupling mode of the measuring
circuit, which was a slow process.
Key words bacteriorhodopsin； light-driven proton pump； pulse response； differential response
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