Linked Life Data

12828639

Source:http://linkedlifedata.com/resource/pubmed/id/12828639

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-6-27
pubmed:abstractText
The interaction of Streptococcus pneumoniae with human plasmin(ogen) represents a mechanism to enhance bacterial virulence by capturing surface-associated proteolytic activity in the infected host. Plasminogen binds to surface displayed pneumococcal alpha-enolase (Eno) and is subsequently activated to the serine protease plasmin by host-derived tissue plasminogen activator (tPA) or urokinase (uPA). The C-terminal lysyl residues of Eno at position 433 and 434 were identified as a binding site for the kringle motifs of plasmin(ogen) which contain lysine binding sites. In this report we have identified a novel internal plamin(ogen)-binding site of Eno by investigating the protein-protein interaction. Plasmin(ogen)-binding activity of C-terminal mutated Eno proteins used in binding assays as well as surface plasmon resonance studies suggested that an additional binding motif of Eno is involved in the Eno-plasmin(ogen) complex formation. The analysis of spot synthesized synthetic peptides representing Eno sequences identified a peptide of nine amino acids located between amino acids 248-256 as the minimal second binding epitope mediating binding of plasminogen to Eno. Binding of radiolabelled plasminogen to viable pneumococci was competitively inhibited by a synthetic peptide FYDKERKVYD representing the novel internal plasmin(ogen)-binding motif of Eno. In contrast, a synthetic peptide with amino acid substitutions at critical positions in the internal binding motif identified by systematic mutational analysis did not inhibit binding of plasminogen to pneumococci. Pneumococcal mutants expressing alpha-enolase with amino acid substitutions in the internal binding motif showed a substantially reduced plasminogen-binding activity. The virulence of these mutants was also attenuated in a mouse model of intranasal infection indicating the significance of the novel plasminogen-binding motif in the pathogenesis of pneumococcal diseases.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
49
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
411-23
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Identification of a novel plasmin(ogen)-binding motif in surface displayed alpha-enolase of Streptococcus pneumoniae.
pubmed:affiliation
Department of Microbial Pathogenicity, GBF-German Research Centre for Biotechnology, 38124 Braunschweig, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't