Linked Life Data

2322

Source:http://linkedlifedata.com/resource/pubmed/id/2322

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1976-4-23
pubmed:abstractText
We have examined the bacteriochlorophyll reaction-center complex of Chlorobium limicola f. thiosulfatophilum, strain Tassajara. Our results indicate that the midpoint potential of the primary electron donor bacteriochlorophyll of the reaction center is +250 mV at pH 6.8, while that of cytochrome c-553 is +165 mV. There are two cytochrome c-553 hemes per reaction center, and the light-induced oxidation of each is biphasic (t1/2 of less than 5 mus and approximately 50 mus). We belive that this indicates a two state equilibrium with each cytochrome heme being either close to, or a little removed from, the reaction-center bacteriochlorophyll. We have also titrated the primary electron acceptor of the reaction center. Its equilibrium midpoint potential at pH 6.8 is below -450 mV. This is very much lower than the previous estimate for green bacteria, and also substantially lower than values obtained for purple bacteria. Such a low-potential primary acceptor would be thermodynamically capable of direct reduction of NAD+ via ferredoxin in a manner analagous to photosystem I in chloroplasts and blue-green algae.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
423
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
357-62
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1976
pubmed:articleTitle
Some thermodynamic and kinetic properties of the primary photochemical reactants in a complex from a green photosynthetic bacterium.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.