Mapping of possible laminin binding sites of Y. pestis plasminogen activator (Pla) via phage display

We tried to determine amino acid motifs of Y. pestis plasminogen activator (Pla) involved in laminin binding. We selected heptamer peptides using a random phage library which was tested against immobilised laminin. Two sequences seemed to inhibit Pla mediated laminin binding of E. coli and exhibited a strong laminin binding capacity revealing a competition with Pla for the same laminin binding site. The motifs are also involved in plasminogen activation because they caused fibrinolysis on fibrin films. The patterns were localised outside the putative surface-exposed loops (Kukkonen et al., 2001).