Primary photochemistry in the facultative green photosynthetic bacterium Chloroflexus aurantiacus

Robert E. Blankenship; Reiner Feick; Barry D. Bruce; Christine Kirmaier; Dewey Holten; R. Clinton Fuller

doi:10.1002/jcb.240220407

Primary photochemistry in the facultative green photosynthetic bacterium Chloroflexus aurantiacus

Robert E. Blankenship
, Reiner Feick
, Barry D. Bruce
, Christine Kirmaier
, Dewey Holten
, R. Clinton Fuller

Department of Chemistry

Research output: Contribution to journal › Article › peer-review

52 Scopus citations

Abstract

The mechanism of primary photochemistry has been investigated in purified cytoplasmic membranes and isolated reaction centers of Chloroflexus aurantiacus. Redox titrations on the cytoplasmic membranes indicate that the midpoint redox potential of P870, the primary electron donor bacteriochlorophyll, is +362 mV. An early electron acceptor, presumably menaquinone has E_m 8.1 = −50 mV, and a tightly bound photooxidizable cytochrome c554 has E_m 8.1 = +245 mV. The isolated reaction center has a bacteriochlorophyll to bacteriopheophytin ratio of 0.94:1. A two‐quinone acceptor system is present, and is inhibited by o‐phenanthroline. Picosecond transient absorption and kinetic measurements indicate the bacteriopheophytin and bacteriochlorophyll form an earlier electron acceptor complex.

Original language	English
Pages (from-to)	251-261
Number of pages	11
Journal	Journal of cellular biochemistry
Volume	22
Issue number	4
DOIs	https://doi.org/10.1002/jcb.240220407
State	Published - 1983

Keywords

bacterial reaction centers
bacteriochlorophyll
bacteriopheophytin
Chloroflexus aurantiacus
menaquinone
primary photochemistry
reaction centers
ubiquinone

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10.1002/jcb.240220407

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title = "Primary photochemistry in the facultative green photosynthetic bacterium Chloroflexus aurantiacus",

abstract = "The mechanism of primary photochemistry has been investigated in purified cytoplasmic membranes and isolated reaction centers of Chloroflexus aurantiacus. Redox titrations on the cytoplasmic membranes indicate that the midpoint redox potential of P870, the primary electron donor bacteriochlorophyll, is +362 mV. An early electron acceptor, presumably menaquinone has Em 8.1 = −50 mV, and a tightly bound photooxidizable cytochrome c554 has Em 8.1 = +245 mV. The isolated reaction center has a bacteriochlorophyll to bacteriopheophytin ratio of 0.94:1. A two‐quinone acceptor system is present, and is inhibited by o‐phenanthroline. Picosecond transient absorption and kinetic measurements indicate the bacteriopheophytin and bacteriochlorophyll form an earlier electron acceptor complex.",

keywords = "bacterial reaction centers, bacteriochlorophyll, bacteriopheophytin, Chloroflexus aurantiacus, menaquinone, primary photochemistry, reaction centers, ubiquinone",

author = "Blankenship, \{Robert E.\} and Reiner Feick and Bruce, \{Barry D.\} and Christine Kirmaier and Dewey Holten and Fuller, \{R. Clinton\}",

year = "1983",

doi = "10.1002/jcb.240220407",

language = "English",

volume = "22",

pages = "251--261",

journal = "Journal of cellular biochemistry",

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TY - JOUR

T1 - Primary photochemistry in the facultative green photosynthetic bacterium Chloroflexus aurantiacus

AU - Blankenship, Robert E.

AU - Feick, Reiner

AU - Bruce, Barry D.

AU - Kirmaier, Christine

AU - Holten, Dewey

AU - Fuller, R. Clinton

PY - 1983

Y1 - 1983

N2 - The mechanism of primary photochemistry has been investigated in purified cytoplasmic membranes and isolated reaction centers of Chloroflexus aurantiacus. Redox titrations on the cytoplasmic membranes indicate that the midpoint redox potential of P870, the primary electron donor bacteriochlorophyll, is +362 mV. An early electron acceptor, presumably menaquinone has Em 8.1 = −50 mV, and a tightly bound photooxidizable cytochrome c554 has Em 8.1 = +245 mV. The isolated reaction center has a bacteriochlorophyll to bacteriopheophytin ratio of 0.94:1. A two‐quinone acceptor system is present, and is inhibited by o‐phenanthroline. Picosecond transient absorption and kinetic measurements indicate the bacteriopheophytin and bacteriochlorophyll form an earlier electron acceptor complex.

AB - The mechanism of primary photochemistry has been investigated in purified cytoplasmic membranes and isolated reaction centers of Chloroflexus aurantiacus. Redox titrations on the cytoplasmic membranes indicate that the midpoint redox potential of P870, the primary electron donor bacteriochlorophyll, is +362 mV. An early electron acceptor, presumably menaquinone has Em 8.1 = −50 mV, and a tightly bound photooxidizable cytochrome c554 has Em 8.1 = +245 mV. The isolated reaction center has a bacteriochlorophyll to bacteriopheophytin ratio of 0.94:1. A two‐quinone acceptor system is present, and is inhibited by o‐phenanthroline. Picosecond transient absorption and kinetic measurements indicate the bacteriopheophytin and bacteriochlorophyll form an earlier electron acceptor complex.

KW - bacterial reaction centers

KW - bacteriochlorophyll

KW - bacteriopheophytin

KW - Chloroflexus aurantiacus

KW - menaquinone

KW - primary photochemistry

KW - reaction centers

KW - ubiquinone

UR - https://www.scopus.com/pages/publications/0021008158

U2 - 10.1002/jcb.240220407

DO - 10.1002/jcb.240220407

M3 - Article

C2 - 6671994

AN - SCOPUS:0021008158

SN - 0730-2312

VL - 22

SP - 251

EP - 261

JO - Journal of cellular biochemistry

JF - Journal of cellular biochemistry

IS - 4

ER -

Primary photochemistry in the facultative green photosynthetic bacterium Chloroflexus aurantiacus

Abstract

Keywords

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