Linked Life Data

2722967

Source:http://linkedlifedata.com/resource/pubmed/id/2722967

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1989-7-5
pubmed:abstractText
The role of aspartic acid-49 (Asp-49) in the active site of porcine pancreatic phospholipase A2 was studied by recombinant DNA techniques: two mutant proteins were constructed containing either glutamic acid (Glu) or lysine (Lys) at position 49. Enzymatic characterization indicated that the presence of Asp-49 is essential for effective hydrolysis of phospholipids. Conversion of Asp-49 to either Glu or Lys strongly reduces the binding of Ca2+ ions, in particular for the lysine mutant, but the affinity for substrate analogues is hardly affected. Extensive purification of naturally occurring Lys-49 phospholipase A2 from the venom of Agkistrodon piscivorus piscivorus yielded a protein that was nearly inactive. Inhibition studies showed that this residual activity was due to a small amount of contaminating enzyme and that the Lys-49 homologue itself has no enzymatic activity. Our results indicate that Asp-49 is essential for the catalytic action of phospholipase A2. The importance of Asp-49 was further evaluated by comparison of the primary sequences of 53 phospholipases A2 and phospholipase homologues showing that substitutions at position 49 are accompanied by structural variations of otherwise conserved residues. The occurrence of several nonconserved substitutions appeared to be a general characteristic of nonactive phospholipase A2 homologues.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0730-2312
pubmed:author
pubmed:issnType
Print
pubmed:volume
39
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
379-90
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
The role of Asp-49 and other conserved amino acids in phospholipases A2 and their importance for enzymatic activity.
pubmed:affiliation
Department of Biochemistry, State University of Utrecht, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't