Linked Life Data

15326166

Source:http://linkedlifedata.com/resource/pubmed/id/15326166

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
44
pubmed:dateCreated
2004-10-25
pubmed:databankReference
pubmed:abstractText
UDP-sugars, activated forms of monosaccharides, are synthesized through de novo and salvage pathways and serve as substrates for the synthesis of polysaccharides, glycolipids, and glycoproteins in higher plants. A UDP-sugar pyrophosphorylase, designated PsUSP, was purified about 1,200-fold from pea (Pisum sativum L.) sprouts by conventional chromatography. The apparent molecular mass of the purified PsUSP was 67,000 Da. The enzyme catalyzed the formation of UDP-Glc, UDP-Gal, UDP-glucuronic acid, UDP-l-arabinose, and UDP-xylose from respective monosaccharide 1-phosphates in the presence of UTP as a co-substrate, indicating that the enzyme has broad substrate specificity toward monosaccharide 1-phosphates. Maximum activity of the enzyme occurred at pH 6.5-7.5, and at 45 degrees C in the presence of 2 mm Mg(2+). The apparent K(m) values for Glc 1-phosphate and l-arabinose 1-phosphate were 0.34 and 0.96 mm, respectively. PsUSP cDNA was cloned by reverse transcriptase-PCR. PsUSP appears to encode a protein with a molecular mass of 66,040 Da (600 amino acids) and possesses a uridine-binding site, which has also been found in a human UDP-N-acetylhexosamine pyrophosphorylase. Phylogenetic analysis revealed that PsUSP can be categorized in a group together with homologues from Arabidopsis and rice, which is distinct from the UDP-Glc and UDP-N-acetylhexosamine pyrophosphorylase groups. Recombinant PsUSP expressed in Escherichia coli catalyzed the formation of UDP-sugars from monosaccharide 1-phosphates and UTP with efficiency similar to that of the native enzyme. These results indicate that the enzyme is a novel type of UDP-sugar pyrophosphorylase, which catalyzes the formation of various UDP-sugars at the end of salvage pathways in higher plants.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Galactosephosphates, http://linkedlifedata.com/resource/pubmed/chemical/Glucosephosphates, http://linkedlifedata.com/resource/pubmed/chemical/Hexosephosphates, http://linkedlifedata.com/resource/pubmed/chemical/Nucleotidyltransferases, http://linkedlifedata.com/resource/pubmed/chemical/Sugar Phosphates, http://linkedlifedata.com/resource/pubmed/chemical/UDPacetylglucosamine..., http://linkedlifedata.com/resource/pubmed/chemical/UTP-Glucose-1-Phosphate..., http://linkedlifedata.com/resource/pubmed/chemical/Uridine Diphosphate Sugars, http://linkedlifedata.com/resource/pubmed/chemical/arabinose-1-phosphate, http://linkedlifedata.com/resource/pubmed/chemical/galactose-1-phosphate, http://linkedlifedata.com/resource/pubmed/chemical/glucose-1-phosphate
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
29
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
45728-36
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
UDP-sugar pyrophosphorylase with broad substrate specificity toward various monosaccharide 1-phosphates from pea sprouts.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, Faculty of Science, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama 338-8570, Japan. kotake@molbiol.saitama-u.ac.jp
pubmed:publicationType
Journal Article