Altmetric

Femtosecond infrared spectroscopy of chlorophyll f-containing photosystem I

File Description SizeFormat 
IR-TAChl-fPSImanuscript-revised-final-tracked.pdfFile embargoed until 10 December 20191.03 MBAdobe PDF    Request a copy
Supplementary Information-PCCP.pdfFile embargoed until 10 December 201981.18 kBAdobe PDF    Request a copy
Title: Femtosecond infrared spectroscopy of chlorophyll f-containing photosystem I
Authors: Zamzam, N
Kaucikas, M
Nurnberg, D
Rutherford, AW
Van Thor, J
Item Type: Journal Article
Abstract: The recent discovery of extremely red-shifted chlorophyll f pigments in both photosystem I (PSI) and photosystem II has led to the conclusion that chlorophyll f plays a role not only in the energy transfer, but also in the charge separation processes [Nürnberg et al., Science, 2018, 360, 1210–1213]. We have employed ultrafast transient infrared absorption spectroscopy to study the contribution of far-red light absorbing chlorophyll f to energy transfer and charge separation processes in far-red light-grown PSI (FRL-PSI) from the cyanobacterium Chroococcidiopsis thermalis PCC 7203. We compare the kinetics and spectra of FRL-grown PSI excited at 670 nm and 740 nm wavelengths to those of white light-grown PSI (WL-PSI) obtained at 675 nm excitation. We report a fast decay of excited state features of chlorophyll a and complete energy transfer from chlorophyll a to chlorophyll f in FRL-PSI upon 670 nm excitation, as indicated by a frequency shift in a carbonyl absorption band occurring within a 1 ps timescale. While the WL-PSI measurements support the assignment of initial charge separation to A−1+˙A0−˙ [Di Donato et al., Biochemistry, 2011, 50, 480–490] from the kinetics of a distinct cation feature at 1710 cm−1, in the case of FRL-PSI, small features at 1715 cm−1 from the chlorophyll cation are present from sub-ps delays instead, supporting the replacement of the A−1 pigment with chlorophyll f. Comparisons of nanosecond spectra show that charge separation proceeds with 740 nm excitation, which selectively excites chlorophyll f, and modifications in specific carbonyl absorption bands assigned to P700+˙ minus P700 and A1−˙ minus A1 indicate dielectric differences of FRL-PSI compared to WL-PSI in one or both of the two electron transfer branches of FRL-PSI.
Issue Date: 21-Jan-2019
Date of Acceptance: 9-Dec-2018
URI: http://hdl.handle.net/10044/1/66728
DOI: https://dx.doi.org/10.1039/C8CP05627G
ISSN: 1463-9076
Publisher: Royal Society of Chemistry
Start Page: 1224
End Page: 1234
Journal / Book Title: Physical Chemistry Chemical Physics
Volume: 21
Copyright Statement: ©the Owner Societies 2019.
Sponsor/Funder: The Leverhulme Trust
Funder's Grant Number: RPG-2014-126
Keywords: Science & Technology
Physical Sciences
Chemistry, Physical
Physics, Atomic, Molecular & Chemical
Chemistry
Physics
ULTRAFAST TRANSIENT ABSORPTION
PRIMARY ELECTRON-TRANSFER
CHLAMYDOMONAS-REINHARDTII
REACTION CENTERS
ENERGY-TRANSFER
PUMP-PROBE
CHARGE SEPARATION
CORE ANTENNA
EXCITATION
DYNAMICS
Chlorophyll
Cyanobacteria
Energy Transfer
Infrared Rays
Kinetics
Photosystem I Protein Complex
Spectrophotometry, Infrared
Synechococcus
02 Physical Sciences
03 Chemical Sciences
Chemical Physics
Publication Status: Published
Embargo Date: 2019-12-10
Online Publication Date: 2018-12-10
Appears in Collections:Faculty of Natural Sciences



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Creative Commonsx