Penicillin binding protein 3 of Staphylococcus aureus NCTC 8325-4 binds and activates human plasminogen.

Sanna Riikka Karoliina Kylväjä, Tuomas Heikki Ilari Ojalehto, Veera Liisa Kainulainen, Ritva Tuula Hannele Virkola, Benita Alice Westerlund-Wikström

Tutkimustuotos: ArtikkelijulkaisuArtikkeliTieteellinenvertaisarvioitu

Abstrakti


Background

Staphylococcus aureus is a versatile pathogen expressing a number of virulence-associated adhesive molecules. In a previous study, we generated in a secretion-competent Escherichia coli strain a library of random FLAG-tag positive (FTP) polypeptides of S. aureus. To identify adhesive proteins and gain additional knowledge on putative virulence factors of S. aureus, we here screened the FTP library against human serum proteins.


Findings

Staphylococcus aureus NCTC 8325-4, origin of the FTP library, adhered to immobilized plasminogen in vitro. In an enzyme-linked immunoassay a C-terminal part of penicillin binding protein 3 (PBP3), included in the FTP library, bound to immobilized plasminogen. We expressed and purified full-length PBP3 and its C-terminal fragments as recombinant proteins. In a time-resolved fluorometry—based assay the PBP3 polypeptides bound to immobilized plasminogen. The polypeptides enhanced formation of plasmin from plasminogen as analyzed by cleavage of a chromogenic plasmin substrate.


Conclusions

The present findings, although preliminary, demonstrate reliably that S. aureus NCTC 8325-4 adheres to immobilized plasminogen in vitro and that the adhesion may be mediated by a C-terminal fragment of the PBP3 protein. The full length PBP3 and the penicillin binding C-terminal domain of PBP3 expressed as recombinant proteins bound plasminogen and activated plasminogen to plasmin. These phenomena were inhibited by the lysine analogue ε-aminocaproic acid suggesting that the binding is mediated by lysine residues. A detailed molecular description of surface molecules enhancing the virulence of S. aureus will aid in understanding of its pathogenicity and help in design of antibacterial drugs in the future
Alkuperäiskielienglanti
Artikkeli389
LehtiBMC research notes
Vuosikerta9
Sivumäärä10
ISSN1756-0500
DOI - pysyväislinkit
TilaJulkaistu - 4 elokuuta 2016
OKM-julkaisutyyppiA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä, vertaisarvioitu

Tieteenalat

  • 1183 Kasvibiologia, mikrobiologia, virologia
  • 1182 Biokemia, solu- ja molekyylibiologia

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