Linked Life Data

7744741

Source:http://linkedlifedata.com/resource/pubmed/id/7744741

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
1995-6-15
pubmed:abstractText
Using a high performance liquid chromatography (HPLC)-based assay, we have demonstrated that isolated oat etioplasts convert the linear tetrapyrrole biliverdin IX alpha to (3E)-phytochromobilin, the proposed precursor of the chromophore of the plant photoreceptor phytochrome. In addition to (3E)-phytochromobilin, the synthesis of a second phytochromobilin was detected by its ability to functionally assemble with recombinant oat apophytochrome A. The structure of this new pigment has been determined to be the 3Z isomer of phytochromobilin by absorption and 1H NMR spectroscopy. Like (3E)-phytochromobilin, assembly of HPLC-purified (3Z)-phytochromobilin with apophytochrome yielded a holoprotein that is spectrally indistinguishable from native oat phytochrome A. However, the postchromatographic conversion of (3Z)- to (3E)-phytochromobilin appears to be responsible for this result. Kinetic HPLC analyses have demonstrated that (3Z)-phytochromobilin is synthesized prior to the 3E isomer by oat etioplasts. We therefore propose that (3Z)-phytochromobilin is the immediate product of biliverdin IX alpha reduction by the enzyme phytochromobilin synthase. This implicates the presence of an isomerase that catalyzes the conversion of (3Z)- to (3E)-phytochromobilin, the immediate precursor of the phytochrome A chromophore.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11111-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
(3Z)- and (3E)-phytochromobilin are intermediates in the biosynthesis of the phytochrome chromophore.
pubmed:affiliation
Section of Molecular and Cellular Biology, University of California, Davis 95616, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.