Linked Life Data

828020

Source:http://linkedlifedata.com/resource/pubmed/id/828020

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1977-3-21
pubmed:abstractText
Studies are presented of the biliproteins of Anabaena sp. This filamentous cyanobacterium contains three major biliproteins. Whereas two of these, C-phycocyanin and allophycocyanin, are common to all cyanobacteria, the third, phycoerythrocyanin (gammamax approximately 568 nm) has hitherto not been described and its distribution among cyanobacteria appears to be limited. Anabaena variabilis and Anabaena sp. 6411 allophycocyanin, C-phycocyanin, and phycoerythrocyanin were purified to homogeneity and characterized with respect to molecular weight, isoelectric point, absorption spectrum and amino acid composition. The alpha and beta subunits of each of these proteins were also purified to homogeneity and characterized in the same manner. The tetrapyrrole chromophore content was determined for each of the proteins and subunits. The alpha subunit of phycoerythrocyanin carries a novel phycobiliviolin-like chromophore. This chromophore has not previously been detected in cyanobacterial biliproteins, but has been noted as a prosthetic group of a cryptophytan phycocyanin. Sedimentation equilibrium studies show that at pH 7.0, at protein concentrations of 0.2-0.6 mg/ml, allophycocyanin, C-phycocyanin and phycoerythrocyanin, each exists as a trimeric aggregate, (alphabeta)3, of molecular weight of approximately 105000. Structrual studies of microcrystals of these three biliproteins by electron microscopy and X-ray diffraction reveal a common plan for the construction of higher assembly forms. The major building block appears to be the trimer (alphabeta)3. It is proposed that this is a disc-like structure about 3.0 X 12.0 nm. The individual alpha or beta subunits are roughly spherical, 3 nm in diameter. Allophycocyanin trimers stack to form bundles of rods which form long needles. Both phycocyanin and phycoerythrocyanin form double discs (alphabeta)6 which are visible as ring-shaped structures by electron microscopy. The mode of assembly of the biliprotein structures in the phycobilisome is, as yet, unknown.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0302-8933
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
110
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
61-75
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1976
pubmed:articleTitle
Characterization and structural properties of the major biliproteins of Anabaena sp.
pubmed:publicationType
Journal Article