The Beck Laboratory
Professor Warren F. Beck
Carotenoids. Two current projects focus on excitation energy transfer and photoprotection mechanisms involving carotenoids in photosynthetic light-harvesting proteins.
In a continuing collaboration with Professor Harry A. Frank (UConn), we are studying excitation energy transfer mechanisms in the peridinin–chlorophyll a protein (PCP) from dinoflagellates. The carbonyl-substituted carotenoid called peridinin serves in PCP as a mid-visible light-harvesting chromophore.
In addition, with Professor Cheryl Kerfeld (MSU-DOE Plant Research Laboratory) and her group, we have recently started work on the photoactivation and photoprotection mechanisms used by the orange carotenoid protein (OCP). Here, carbonyl-substituted carotenoids (3'-hydroxyechinenone or canthaxanthin) serve as quenchers of bilin excited states in the phycobilisome when OCP is in the active or red state (OCPR). These carotenoids also serve as quenchers of singlet oxygen, a reactive oxygen species that is produced naturally in oxygenic photosynthesis.
Coherence. In a new collaboration with the laboratory of Professor Marcos Dantus (Department of Chemistry), we are working towards development of new methods applying shaped ultrashort excitation pulses to detect electronic coherences (delocalized excited states) in bulk materials and in microscopic imaging applications.
Methods. In all of this work, we use state-of-the-art femtosecond nonlinear spectroscopic methods, including two-dimensional electronic spectroscopy (2DES) and transient-grating spectroscopies. We have recently installed a high-repetition rate femtosecond Yb amplifier and a noncollinear optical parametric amplifier (NOPA) that has greatly accellerated our progress. Combined with a pair of adaptive pulse shapers, this laser system produces <10 fs pulses with output tunable over most of the the visible region of the spectrum.
The Beck laboratory is supported by the DOE/BES Photosynthetic Systems program (award DE-SC0010847).