Harvesting light by the second photosynthetic system: Bacteriorhodopsin

Dieter Oesterhelt

Max-Planck-Institute for Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany

e-mail: oesterhe@biochem.mpg.de

URL: http://www.biochem.mpg.de/en/eg/oesterhelt/index.html


After a general introduction to halophilic archaea as carriers of bacteriorhodospin the principle of light driven ion pumps will be extended to proteorhodopsins in marine bacteria. This will be followed by a comparison between the chlorophyll and retinal systems in light energy conversion.

In a more specific part the molecular properties of bacteriorhodopsin will be described which allow this proton pump to become resistant to long term irradiation and to shift its thermodynamic efficiency into the physiological active range. These two essential features are the molecular basis of purple membrane formation in the cell and the conformationl changes accompanying its active catalytic cycle.