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Evidence of Simultaneous Spectral Hole Burning Involving Two Tiers of the Protein Energy Landscape in Cytochrome b6f.

Author(s): Shafiei G, Levenberg A, Lujan MA, Picorel R, Zazubovich V

J Phys Chem B. 2019 Dec 12;: Authors: Shafiei G, Levenberg A, Lujan MA, Picorel R, Zazubovich V

Article GUID: 31763829
Conformational Changes in Pigment-Protein Complexes at Low Temperatures-Spectral Memory and a Possibility of Cooperative Effects.

Author(s): Najafi M, Herascu N, Shafiei G, Picorel R, Zazubovich V

J Phys Chem B. 2015 Jun 11;119(23):6930-40 Authors: Najafi M, Herascu N, Shafiei G, Picorel R, Zazubovich V

Article GUID: 25985255
Probing Energy Landscapes of Cytochrome b6f with Spectral Hole Burning: Effects of Deuterated Solvent and Detergent.

Author(s): Levenberg A, Shafiei G, Lujan MA, Giannacopoulos S, Picorel R, Zazubovich V

J Phys Chem B. 2017 10 26;121(42):9848-9858 Authors: Levenberg A, Shafiei G, Lujan MA, Giannacopoulos S, Picorel R, Zazubovich V

Article GUID: 28956922
Spectral Hole Burning in Cyanobacterial Photosystem I with P700 in Oxidized and Neutral States.

Author(s): Herascu N, Hunter MS, Shafiei G, Najafi M, Johnson TW, Fromme P, Zazubovich V

J Phys Chem B. 2016;120(40):10483-10495 Authors: Herascu N, Hunter MS, Shafiei G, Najafi M, Johnson TW, Fromme P, Zazubovich V

Article GUID: 27661089
Title:Evidence of Simultaneous Spectral Hole Burning Involving Two Tiers of the Protein Energy Landscape in Cytochrome b6f.
Authors:Shafiei G,  Levenberg A,  Lujan MA,  Picorel R,  Zazubovich V
Link:https://www.ncbi.nlm.nih.gov/pubmed/31763829?dopt=Abstract
DOI:10.1021/acs.jpcb.9b09515
Category:J Phys Chem B
PMID:31763829
Dept Affiliation: PHYSICS
1 Department of Physics , Concordia University , 7141 Sherbrooke Str. West , Montreal , Quebec H4B 1R6 , Canada.
2 Estacion Experimental de Aula Dei (CSIC) , Avda. Montañana 1005 , 50059 Zaragoza , Spain.

Description:

Evidence of Simultaneous Spectral Hole Burning Involving Two Tiers of the Protein Energy Landscape in Cytochrome b6f.

J Phys Chem B. 2019 Dec 12;:

Authors: Shafiei G, Levenberg A, Lujan MA, Picorel R, Zazubovich V

Abstract

Cytochrome b6f, with one chlorophyll molecule per protein monomer, is a simple model system whose studies can help achieve a better understanding of nonphotochemical spectral hole burning (NPHB) and single-complex spectroscopy results obtained in more complicated photosynthetic chlorophyll-protein complexes. We are reporting new data and proposing an alternative explanation for spectral dynamics that was recently observed in cytochrome b6f using NPHB. The relevant distribution of the tunneling parameter ? is a superposition of two components that are nearly degenerate in terms of the resultant NPHB yield and represent two tiers of the energy landscape responsible for NPHB. These two components likely burn competitively; we present the first demonstration of modeling a competitive NPHB process. Similar values of the NPHB yield result from distinctly different combinations of barrier heights, shifts along the generalized coordinate d, and/or masses of the entities involved in conformational changes m, with md2 parameter different by a factor of 2.7. Consequently, in cytochrome b6f, the first (at least) 10 h of fixed-temperature recovery preferentially probe different components of the barrier- and ?-distributions encoded into the spectral holes than thermocycling experiments. Both components most likely represent dynamics of the protein and not of the surrounding buffer/glycerol glass.

PMID: 31763829 [PubMed - as supplied by publisher]