Linked Life Data

3902830

Source:http://linkedlifedata.com/resource/pubmed/id/3902830

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
26
pubmed:dateCreated
1985-12-13
pubmed:databankReference
pubmed:abstractText
The pyruvate oxidase of Escherichia coli is a homo-tetrameric enzyme which can be activated greater than 500-fold (kcat/Km) by limited proteolytic digestion with alpha-chymotrypsin in the presence of pyruvate and thiamine pyrophosphate. The cleavage produces an Mr 2000 peptide (the alpha-peptide) from each subunit and mimics the physiologically important activation of the enzyme by phospholipids. Moreover, the proteolytic cleavage results in the loss of the high affinity lipid-binding site of the enzyme. We now report the isolation and characterization of the alpha-peptide fragment which is cleaved from the carboxyl terminus of each subunit by protease activation. Both the site of cleavage and the sequence of the alpha-peptide have been determined by a combination of Edman degradation of the purified peptide and DNA sequence analysis of the gene encoding the oxidase. The cleavage site lies within a sequence of hydrophobic amino acids predicted to form a beta-sheet. Another segment of the alpha-peptide is predicted to form an amphipathic alpha-helix. Quantitative assessment of the amphipathic nature of this alpha-helix (Eisenberg, D. (1984) Annu. Rev. Biochem. 53, 595-623) gives a value very similar to the values for several helical peptides which spontaneously bind to the surface of phospholipid vesicles. From these analyses, we propose that the alpha-peptide may play a role in binding pyruvate oxidase to cell membrane phospholipids in vivo.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
260
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14287-91
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Characterization of the alpha-peptide released upon protease activation of pyruvate oxidase.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.