title: Spectroscopic Studies of Cryptophyte Light Harvesting Proteins: Vibrations and Coherent Oscillations.
abstract: The first step of photosynthesis is the absorption of light by antenna complexes. Recent studies of light-harvesting complexes using two-dimensional electronic spectroscopy have revealed interesting coherent oscillations. Some contributions to those coherences are assigned to electronic coherence and therefore have implications for theories of energy transfer. To assign these femtosecond data and to gain insight into the interplay among electronic and vibrational resonances, we need detailed information on vibrations and coherences in the excited electronic state compared to the ground electronic state. Here, we used broad-band transient absorption and femtosecond stimulated Raman spectroscopies to record ground- and excited-state coherences in four related photosynthetic proteins: PC577 from Hemiselmis pacifica CCMP706, PC612 from Hemiselmis virescens CCAC 1635 B, PC630 from Chroomonas CCAC 1627 B (marine), and PC645 from Chroomonas mesostigmatica CCMP269. Two of those proteins (PC630 and PC645) have strong electronic coupling while the other two proteins (PC577 and PC612) have weak electronic coupling between the chromophores. We report vibrational spectra for the ground and excited electronic states of these complexes as well as an analysis of coherent oscillations observed in the broad-band transient absorption data.
authors.affiliation: †Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Paul C
authors.initials: PC
authors.lastname: Arpin
authors.affiliation: †Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Turner
authors.affiliation: †Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Scott D
authors.initials: SD
authors.lastname: McClure
authors.affiliation: †Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Chanelle C
authors.initials: CC
authors.lastname: Jumper
authors.affiliation: †Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Tihana
authors.initials: T
authors.lastname: Mirkovic
authors.affiliation: ‡Department of Chemistry, University of Rochester, Rochester, New York 14627, United States.
authors.forename: J Reddy
authors.initials: JR
authors.lastname: Challa
authors.affiliation: ‡Department of Chemistry, University of Rochester, Rochester, New York 14627, United States.
authors.forename: Joohyun
authors.initials: J
authors.lastname: Lee
authors.affiliation: §Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
authors.forename: Chang Ying
authors.initials: CY
authors.lastname: Teng
authors.affiliation: §Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
authors.forename: Beverley R
authors.initials: BR
authors.lastname: Green
authors.affiliation: ∥School of Physics, The University of New South Wales, Sydney, New South Wales 2052, Australia.
authors.forename: Krystyna E
authors.initials: KE
authors.lastname: Wilk
authors.affiliation: ∥School of Physics, The University of New South Wales, Sydney, New South Wales 2052, Australia.
authors.forename: Paul M G
authors.initials: PM
authors.lastname: Curmi
authors.affiliation: ⊥Botanical Institute, Cologne Biocenter, University of Cologne, 50674 Cologne, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Hoef-Emden
authors.affiliation: ‡Department of Chemistry, University of Rochester, Rochester, New York 14627, United States.
authors.forename: David W
authors.initials: DW
authors.lastname: McCamant
authors.affiliation: †Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada.|#Department of Chemistry, Princeton University, Washington Road, Princeton, New Jersey 08544, United States.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Scholes
mesh_terms: D044785:Cryptophyta / Q000737:chemistry*; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry*; D008958:Models, Molecular; D013057:Spectrum Analysis; D014732:Vibration
chemical_list: D045342:Light-Harvesting Protein Complexes