Linked Life Data

3022806

Source:http://linkedlifedata.com/resource/pubmed/id/3022806

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
1987-1-15
pubmed:abstractText
Cytochrome c1 from a photosynthetic bacterium Rhodobacter sphaeroides R-26 has been purified to homogeneity. The purified protein contains 30 nmol heme per mg protein, has an isoelectric point of 5.7, and is soluble in aqueous solution in the absence of detergents. The apparent molecular weight of this protein is about 150,000, determined by Bio Gel A-0.5 m column chromatography; a minimum molecular weight of 30,000 is obtained by sodium dodecylsulfate polyacrylamide gel electrophoresis. The absorption spectrum of this cytochrome is similar to that of mammalian cytochrome c1, but the amino acid composition and circular dichroism spectral characteristics are different. The heme moiety of cytochrome c1 is more exposed than is that of mammalian cytochrome c1, but less exposed than that of cytochrome c2. Ferricytochrome c1 undergoes photoreduction upon illumination with light under anaerobic conditions. Such photoreduction is completely abolished when p-chloromercuriphenylsulfonate is added to ferricytochrome c1, suggesting that the sulfhydryl groups of cytochrome c1 are the electron donors for photoreduction. Purified cytochrome c1 contains 3 +/- 0.1 mol of the p-chloromercuriphenylsulfonate titratable sulfhydryl groups per mol of protein. In contrast to mammalian cytochrome c1, the bacterial protein does not form a stable complex with cytochrome c2 or with mammalian cytochrome c at low ionic strength. Electron transfer between bacterial ferrocytochrome c1 and bacterial ferricytochrome c2, and between bacterial ferrocytochrome c1 and mammalian ferricytochrome c proceeds rapidly with equilibrium constants of 49 and 3.5, respectively. The midpoint potential of purified cytochrome c1 is calculated to be 228 mV, which is identical to that of mammalian cytochrome c1.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
852
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
203-11
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Characterization of purified cytochrome c1 from Rhodobacter sphaeroides R-26.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't