Linked Life Data

1521537

Source:http://linkedlifedata.com/resource/pubmed/id/1521537

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1992-10-13
pubmed:databankReference
pubmed:abstractText
1. Limited proteolysis of citrate synthase from Sulfolobus solfataricus by trypsin reduced the rate of the overall reaction (acetyl-CoA + oxaloacetate + H2O----citrate + CoASH) to 4% but did not affect the hydrolysis of citryl-CoA. Experimental results indicate that a connecting link between the enzyme's ligase and hydrolase activity becomes impaired specifically on treatment with trypsin. Other proteolytic enzymes like chymotrypsin and subtilisin inactivated catalytic functions of citrate synthase, ligase and hydrolase, equally well. 2. Tryptic hydrolysis occurs at the N-terminal region of citrate synthase, but a study by SDS/PAGE revealed no difference in molecular mass between native and proteolytically nicked citrate synthase. The peptide removed from the enzyme by trypsin, therefore, contains less than about 15 amino acid residues. 3. The Km values of the substrates for both native and nicked enzyme were identical, as was the state of aggregation (dimeric) of the two enzyme species. These could be separated by affinity chromatography on Blue-Sepharose and differentiated by their isoelectric points (pI = 6.68 +/- 0.08 and pI = 6.37 +/- 0.03 for native citrate synthase and the large tryptic peptide, respectively) as well as by the N-terminus which is blocked in the native enzyme only. 4. Edman degradation of the large tryptic fragment yielded the N-terminal sequence GLEDVYIKSTSLTYIDGVNGVLRY, which is 71% identical to the N-terminal region (positions 9-32) of citrate synthase from Thermoplasma acidophilum. 5. The conversion of citrate synthase into essentially a citryl-CoA hydrolase is considered the consequence of a conformational change thought to occur on tryptic removal of the N-terminal small peptide.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
208
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
459-66
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Conversion, by limited proteolysis, of an archaebacterial citrate synthase into essentially a citryl-CoA hydrolase.
pubmed:affiliation
Institut für Physiologische Chemie, Technischen Universität München, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't