Linked Life Data

8241180

Source:http://linkedlifedata.com/resource/pubmed/id/8241180

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
48
pubmed:dateCreated
1994-1-6
pubmed:abstractText
Kinetics of flash-induced electron transfer from the soluble cytochrome c2 to the primary donor (P) of the reaction center purified from the purple bacterium Rhodobacter sphaeroides R-26 were investigated by time-resolved absorption spectroscopy. Re-reduction of P+ induced by a laser pulse was measured at 1283 nm both in isolated reaction centers and in reconstituted proteoliposomes reproducing the lipid composition of the native membrane. The effects of temperature (230-300 K) and of the cytochrome c2/reaction center stoichiometry were examined. At room temperature, over a wide range of cytochrome c2 to reaction center molar ratios, the biphasic kinetics of cytochrome c2 oxidation in the microsecond-to-millisecond time scale could be accurately described by a minimum reaction scheme which includes a second-order collisional process (k = 1.4 x 10(9) M-1 s-1 and k = 2.4 x 10(9) M-1 s-1 in isolated and reconstituted reaction centers, respectively) and a first-order intracomplex electron donation (t1/2 = 590 +/- 110 ns in isolated reaction centers; t1/2 = 930 +/- 140 ns in proteoliposomes). At cytochrome c2 to reaction center molar ratios exceeding 5, the monomolecular process almost completely accounts for P+ re-reduction. At lower stoichiometries, the relative contribution of the two parallel reaction pathways is modulated by a single binding equilibrium between cytochrome c2 and reaction centers, yielding a binding constant of 3.5 x 10(5) M-1 in both systems.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13245-53
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Electron transfer from cytochrome c2 to the primary donor of Rhodobacter sphaeroides reaction centers. A temperature dependence study.
pubmed:affiliation
Dipartimento di Biologia, Università di Bologna, Italy.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't