Hannover 2010 – scientific programme

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MO: Fachverband Molekülphysik

MO 17: Biomolecules

MO 17.8: Talk

Wednesday, March 10, 2010, 18:15–18:30, F 142

Simultaneous observation of ultrafast ligand dissociation and docking-site trapping in heme proteins using upconversion infrared spectroscopy — •Patrick Nuernberger, Kevin F. Lee, Adeline Bonvalet, Marten H. Vos, and Manuel Joffre — Laboratoire d’Optique et Biosciences, Ecole Polytechnique, Centre National de la Recherche Scientifique, 91128 Palaiseau, France, and Institut National de la Santé et de la Recherche Médicale, U696, 91128 Palaiseau, France

We report on ultrafast visible pump/mid-infrared probe spectroscopy of the carboxy form of heme proteins by employing the recently developed chirped-pulse upconversion technique, which allows both high resolution and sensitivity over an extremely broad spectral range. Commonly, the bleach signal due to ligand dissociation and the incipient docking-site absorption signal, being about 200 cm⁻¹ apart and differing by more than an order of magnitude in absorptivity, are studied individually. We here monitor them simultaneously, allowing a direct observation and a concurrent analysis of the initial processes after photoinduced ligand dissociation, for instance the formation of hot vibrational bands.