Controlling the pathway of photosynthetic charge separation in bacterial reaction centers

A. L M Haffa, S. Lin, J. C. Williams, B. P. Bowen, A. K W Taguchi, James Paul Allen, N. W. Woodbury

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

For at least 2 billion years, the structure of the photosynthetic reaction center has maintained an approximate rotational symmetry, in both plants and bacteria, consisting of a heterodimeric core with two ostensibly similar electron-transfer pathways, yet the functional advantage of this symmetry is not clear. This structure/function enigma is nowhere more apparent than in reaction centers isolated from the photosynthetic bacterium Rhodobacter (Rb.) sphaeroides. These reaction centers possess two approximately symmetric potential electron transfer pathways (labeled A and B), but stable charge separation is only observed along the A-side in isolated wild type reaction centers. Here we demonstrate that the introduction of two protonatable residues (aspartate and glutamate) in the vicinity of the cofactors involved in initial electron transfer results in pH-dependent switching between A- and B-side charge separation products. At pH 7.2, A-side photochemistry predominates, whereas at pH 9.5, a long-lived B-side charge-separated state is formed almost exclusively. This raises the possibility that a similar control of wild type reaction centers could be mediated either by external factors or by photochemically induced electrostatic changes in vivo.

Original languageEnglish
Pages (from-to)4-7
Number of pages4
JournalJournal of Physical Chemistry B
Volume108
Issue number1
Publication statusPublished - Jan 8 2004

Fingerprint

polarization (charge separation)
Electrons
Bacteria
electron transfer
Photosynthetic Reaction Center Complex Proteins
Photochemical reactions
bacteria
Aspartic Acid
Glutamic Acid
Electrostatics
aspartates
glutamates
symmetry
photochemical reactions
electrostatics
products

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Haffa, A. L. M., Lin, S., Williams, J. C., Bowen, B. P., Taguchi, A. K. W., Allen, J. P., & Woodbury, N. W. (2004). Controlling the pathway of photosynthetic charge separation in bacterial reaction centers. Journal of Physical Chemistry B, 108(1), 4-7.

Controlling the pathway of photosynthetic charge separation in bacterial reaction centers. / Haffa, A. L M; Lin, S.; Williams, J. C.; Bowen, B. P.; Taguchi, A. K W; Allen, James Paul; Woodbury, N. W.

In: Journal of Physical Chemistry B, Vol. 108, No. 1, 08.01.2004, p. 4-7.

Research output: Contribution to journalArticle

Haffa, ALM, Lin, S, Williams, JC, Bowen, BP, Taguchi, AKW, Allen, JP & Woodbury, NW 2004, 'Controlling the pathway of photosynthetic charge separation in bacterial reaction centers', Journal of Physical Chemistry B, vol. 108, no. 1, pp. 4-7.
Haffa, A. L M ; Lin, S. ; Williams, J. C. ; Bowen, B. P. ; Taguchi, A. K W ; Allen, James Paul ; Woodbury, N. W. / Controlling the pathway of photosynthetic charge separation in bacterial reaction centers. In: Journal of Physical Chemistry B. 2004 ; Vol. 108, No. 1. pp. 4-7.
@article{1170de598f7d4f618949cd6379b10349,
title = "Controlling the pathway of photosynthetic charge separation in bacterial reaction centers",
abstract = "For at least 2 billion years, the structure of the photosynthetic reaction center has maintained an approximate rotational symmetry, in both plants and bacteria, consisting of a heterodimeric core with two ostensibly similar electron-transfer pathways, yet the functional advantage of this symmetry is not clear. This structure/function enigma is nowhere more apparent than in reaction centers isolated from the photosynthetic bacterium Rhodobacter (Rb.) sphaeroides. These reaction centers possess two approximately symmetric potential electron transfer pathways (labeled A and B), but stable charge separation is only observed along the A-side in isolated wild type reaction centers. Here we demonstrate that the introduction of two protonatable residues (aspartate and glutamate) in the vicinity of the cofactors involved in initial electron transfer results in pH-dependent switching between A- and B-side charge separation products. At pH 7.2, A-side photochemistry predominates, whereas at pH 9.5, a long-lived B-side charge-separated state is formed almost exclusively. This raises the possibility that a similar control of wild type reaction centers could be mediated either by external factors or by photochemically induced electrostatic changes in vivo.",
author = "Haffa, {A. L M} and S. Lin and Williams, {J. C.} and Bowen, {B. P.} and Taguchi, {A. K W} and Allen, {James Paul} and Woodbury, {N. W.}",
year = "2004",
month = "1",
day = "8",
language = "English",
volume = "108",
pages = "4--7",
journal = "Journal of Physical Chemistry B Materials",
issn = "1520-6106",
publisher = "American Chemical Society",
number = "1",

}

TY - JOUR

T1 - Controlling the pathway of photosynthetic charge separation in bacterial reaction centers

AU - Haffa, A. L M

AU - Lin, S.

AU - Williams, J. C.

AU - Bowen, B. P.

AU - Taguchi, A. K W

AU - Allen, James Paul

AU - Woodbury, N. W.

PY - 2004/1/8

Y1 - 2004/1/8

N2 - For at least 2 billion years, the structure of the photosynthetic reaction center has maintained an approximate rotational symmetry, in both plants and bacteria, consisting of a heterodimeric core with two ostensibly similar electron-transfer pathways, yet the functional advantage of this symmetry is not clear. This structure/function enigma is nowhere more apparent than in reaction centers isolated from the photosynthetic bacterium Rhodobacter (Rb.) sphaeroides. These reaction centers possess two approximately symmetric potential electron transfer pathways (labeled A and B), but stable charge separation is only observed along the A-side in isolated wild type reaction centers. Here we demonstrate that the introduction of two protonatable residues (aspartate and glutamate) in the vicinity of the cofactors involved in initial electron transfer results in pH-dependent switching between A- and B-side charge separation products. At pH 7.2, A-side photochemistry predominates, whereas at pH 9.5, a long-lived B-side charge-separated state is formed almost exclusively. This raises the possibility that a similar control of wild type reaction centers could be mediated either by external factors or by photochemically induced electrostatic changes in vivo.

AB - For at least 2 billion years, the structure of the photosynthetic reaction center has maintained an approximate rotational symmetry, in both plants and bacteria, consisting of a heterodimeric core with two ostensibly similar electron-transfer pathways, yet the functional advantage of this symmetry is not clear. This structure/function enigma is nowhere more apparent than in reaction centers isolated from the photosynthetic bacterium Rhodobacter (Rb.) sphaeroides. These reaction centers possess two approximately symmetric potential electron transfer pathways (labeled A and B), but stable charge separation is only observed along the A-side in isolated wild type reaction centers. Here we demonstrate that the introduction of two protonatable residues (aspartate and glutamate) in the vicinity of the cofactors involved in initial electron transfer results in pH-dependent switching between A- and B-side charge separation products. At pH 7.2, A-side photochemistry predominates, whereas at pH 9.5, a long-lived B-side charge-separated state is formed almost exclusively. This raises the possibility that a similar control of wild type reaction centers could be mediated either by external factors or by photochemically induced electrostatic changes in vivo.

UR - http://www.scopus.com/inward/record.url?scp=1642502268&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=1642502268&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:1642502268

VL - 108

SP - 4

EP - 7

JO - Journal of Physical Chemistry B Materials

JF - Journal of Physical Chemistry B Materials

SN - 1520-6106

IS - 1

ER -