Linked Life Data

2144103

Source:http://linkedlifedata.com/resource/pubmed/id/2144103

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1990-10-3
pubmed:abstractText
Sucrose phosphate synthase (SPS) was isolated from spinach leaves by precipitation with polyethylene glycol, ion-exchange and hydrophobic interaction chromatography, and rate zonal centrifugation. The enzyme was purified more than 600-fold to a specific activity of 57 mumol/min/mg protein. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that a 120-kDa polypeptide was enriched through purification and was the major polypeptide in the final SPS preparation. The 120-kDa polypeptide was photoaffinity labeled with the substrate analog, 5-azidouridine [beta-32P]5'-diphosphate-glucose ([beta-32P]5-N3UDP-Glc). Covalent incorporation of 5-N3UDP-Glc into the 120-kDa polypeptide exhibited an apparent Kd of 74 microM, similar to the apparent Ki for inhibition of SPS activity by unphotolyzed 5-N3UDP-Glc. Competition experiments showed that photolabeling of the 120-kDa polypeptide by 5-N3UDP-Glc was reduced in the presence of UDP-Glc, exhibiting an apparent Ki value that was similar to the apparent Km (UDP-Glc) of 2.9 mM for the purified enzyme. The relative molecular mass of the SPS holoenzyme was 253,000, and the isoelectric point of the 120-kDa subunit was 5.2. The data confirmed the identity of the 120-kDa polypeptide as the SPS subunit, established the structure of the active enzyme as a dimer, and demonstrated active-site labeling of SPS by a photoaffinity analog of the substrate.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
212-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Purification and photoaffinity labeling of sucrose phosphate synthase from spinach leaves.
pubmed:affiliation
U.S. Department of Agriculture, Agricultural Research Service, University of Kentucky, Lexington 40546.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.