Typically, both photo transduction and enzymatic activities occur with the aid of internal co-factors embedded in the protein scaffolding (e.g. chlorophyll in photosynthetic proteins, heme molecules in oxygen binding proteins and vitamins in enzymes). Since proteins are constructed from a combination of 20 naturally occurring amino acids, each with unique properties such as charge, polarity, polarizability and structure, a complex set of potential interactions can result between the protein environment and embedded cofactors. To ensure that biological functions occur efficiently, Nature has fine-tuned the properties of protein environments to optimize specific features of embedded reactions. For example, the electric field from the residues surrounding the chromophore in the Photoactive Yellow Protein manipulates the excited state potential energy surface to generate preferential chemistry, i.e. isomerization of the embedded chromophore in PYP. The identification of these specific protein-cofactor interactions and how they couple to the dynamics underlying biological activity (especially photoactivated activity) is the central goal of our research.
- Substrate and Intensity Dependent Photoenhanced Transamination Reactions of Pyridoxal 5'-Phosphate in Solution, Scott C Corley, Sean M Gottlieb, Delmar S Larsen, Chem. Phys. Letters, 554, 195–200 (2012) pdf
- Ultrafast E to Z Photoisomerization Dynamics of the Cph1 Phytochrome, Peter W. Kim, Jie Pan, Nathan C. Rockwell, Che-Wei Chang, Keenan C. Taylor, J. Clark Lagarias, Delmar S. Larsen, Chem. Phys. Letters, 549, 86–92 (2012). pdf
- Chemical Inhomogeneity in the Ultrafast Dynamics of the DXCF Cyanobacteriochrome Tlr0924, Lucy H. Freer, Peter W. Kim, Scott C. Corley, Nathan C. Rockwell, Lu Zhao, Arthur J. Thibert, J. Clark Lagarias, and Delmar S. Larsen, Journal of Physical Chemistry B, 116 (35), 10571–10581 (2012). pdf
- A Flexible LED-based Broadband Transient-Absorption Spectrometer, Sean M. Gottlieb, Scott C. Corley, Dorte Madsen, and Delmar S. Larsen, Review of Scientific Instruments, 83, 056107 (2012). pdf
- Femtosecond Photodynamics of the Red/Green Cyanobacteriochrome NpR6012g4 from Nostoc punctiforme: 1. Forward Dynamics, Peter W. Kim, Lucy H. Freer, Nathan C. Rockwell, Shelley S. Martin, J. Clark Lagarias, and Delmar S. Larsen, Biochemistry, 51, 608−618 (2012). pdf
- Femtosecond Photodynamics of the Red/Green Cyanobacteriochrome NpR6012g4 from Nostoc punctiforme: 2. Reverse Dynamics, Peter W. Kim, Lucy H. Freer, Nathan C. Rockwell, Shelley S. Martin, J. Clark Lagarias, and Delmar S. Larsen, Biochemistry, 51, 619−630 (2012). pdf
- Second-Chance Initiation Dynamics of the Cyanobacterial Photocycle in the NpR6012 GAF4 Domain of Nostoc Punctiforme, Peter W. Kim, Lucy H. Freer, Nathan C. Rockwell, Shelley S. Martin, J. Clark Lagarias, and Delmar S. Larsen, Journal of the American Chemical Society, 134 (1), 130–133 (2012). pdf
- Sub-Picosecond Excited State Proton Transfer Preceding Isomerization During the Photorecovery of Photoactive Yellow Protein, Elizabeth C. Carroll, Sang-Hun Song, Masato Kumauchi, Ivo H.M. van Stokkum, Askat Jailaubekov, Wouter D. Hoff, and Delmar S. Larsen, Journal of Physical Chemistry Letters 1, 2793–2799 (2010).pdf
- Is the Photoactive Yellow Protein a UV-B/Blue Light Photoreceptor? Elizabeth C. Carroll, Marijke Hospes, Carmen Valladares, Klaas J. Hellingwerf, Delmar S. Larsen, Photochem. Photobiol. Sci., 10 (4), 464 - 468 (2011). pdf
- Primary Photochemistry in the Photoactive Yellow Protein: The Prototype Xanthopsin, Delmar S. Larsen, Rienk van Grondelle, Klaas J. Hellingwerf in Ultrashort Laser Pulses in Biology and Medicine ed. M. Barun, P. Gilch, W. Zinth (2008).