Peter Hegemann is Professor and Head of the Department for Biophysics at the Humboldt University of Berlin, Germany. His research focuses on the characterization of natural sensory photoreceptors, mainly from microalgae. Hegemann has characterized behavioral and photoelectric responses of the unicellular alga Chlamydomonas, a work that cumulated in the claim that the photoreceptors for these responses was a rhodopsin that unified the sensor and ion channel in one protein. He proved this hypothesis by identifying the light-gated channel channelrhodopsin, and by demonstrating its functionality in animal cells.
Hegemann's group also discovered the fundamental principles of the unique channelrhodopsin proteins in molecular detail by a wide range of genomic, biophysical, electrophysiological, and structural techniques with many mutants in close collaboration with Karl Deisseroth, which led to their deciphering of the unprecedented light-gated ion channel mechanism, including its pore gating by photons and its ion selectivity. This basic work also fundamentally enabled optogenetics.
Hegemann studied chemistry in Münster and Munich and earned his PhD in Munich with an investigation into the structure and function of halorhodopsin, a light-driven chloride pump in Halobacterium halobium. As a postdoc, he worked at Syracuse University before starting a research group in the Department of Membrane Biochemistry at the Max-Planck-Institute of Biochemistry in Munich, Germany. He became professor for Biochemistry at the University of Regensburg and was appointed full professor for Biophysics at the Humboldt-University of Berlin in 2004.