English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/58504
Share/Impact:
Statistics
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Title

Spectral hole burning, recovery, and thermocycling in chlorophyll-protein complexes: Distributions of barriers on the protein energy landscape

AuthorsNajafi, Mehdi; Herascu, Nicoleta; Seibert, Michael; Picorel Castaño, Rafael ; Picorel Castaño, Rafael ; Jankowiak, Ryszard J.; Zazubovich, Valter
Issue Date27-Sep-2012
PublisherAmerican Chemical Society
CitationNajafi M, Herascu N, Seibert M, Picorel R, Jankowiak R, Zazubovich V. Spectral hole burning, recovery, and thermocycling in chlorophyll-protein complexes: Distributions of barriers on the protein energy landscape. Journal of Physical Chemistry B 116 (38): 11780-11790 (2012)
AbstractChlorophyll–protein complexes are ideal model systems for protein energy landscape research. Here pigments, used in optical spectroscopy experiments as sensitive probes to local dynamics, are built into protein by Nature (in a large variety of local environments; without extraneous chemical manipulations or genetic engineering). Distributions of the tunneling parameter, λ, and/or protein energy landscape barrier heights, V, have been determined for (the lowest energy state of) the CP43 core antenna complex of photosystem II. We demonstrate that spectral hole burning (SHB) and hole recovery (HR) measurements are capable of delivering important information on protein energy landscape properties and spectral diffusion mechanism details. In particular, we show that tunneling rather than barrier hopping is responsible for both persistent SHB and subsequent HR at 5–12 K, which allows us to estimate the md2 parameter of the tunneling entities as 1.0 × 10–46 kg·m2. The subdistributions of λ actually contributing to the nonsaturated spectral holes (and affecting their recovery) differ from the respective full true distributions. In the case of the full λ-distribution being uniform (or the barrier height distribution 1/√V, a model which has been widely employed in theories of amorphous solids at low temperatures and in HR analysis), the difference is qualitative, with λ subdistributions probed in the HR experiments being highly asymmetrical, and barrier V subdistributions deviating significantly from 1/√V. Thus, the distribution of λ for the protein energy landscape tier directly probed by SHB is likely Gaussian and not uniform. Additionally, a Gaussian distribution of barriers, with parameters incompatible with those of the landscape tier directly probed by SHB, contributes to the thermocycling results.
Description40 Pags. The definitive version, with tabls. and figs., is available at: http://pubs.acs.org/journal/jpcbfk
Publisher version (URL)http://dx.doi.org/10.1021/jp308055r
URIhttp://hdl.handle.net/10261/58504
DOI10.1021/jp308055r
ISSN1520-6106
E-ISSN1520-5207
Appears in Collections:(EEAD) Artículos
Files in This Item:
File Description SizeFormat 
PicorelR_JPhysChemB_2012.pdf258,75 kBAdobe PDFThumbnail
View/Open
Show full item record
Review this work
 

Related articles:


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.