Beschreibung:
<jats:p>Large random hexa‐ and decapenta‐peptide libraries were constructed and displayed on the surface of the filamentous phagemid pComb8. Panning of the hexa‐peptide library on immobilized plasminogen activator inhibitor 1 (PAI‐1) specifically selected a minor fraction of concatemers, indicating that binding to PAI‐1 requires an extended amino acid sequence. Accordingly, the decapenta‐peptide library exclusively yielded PAI‐1 binding peptides of 15 amino acid residues. None of these phage‐bound peptides prevented the interaction between PAI‐1 and its target serine protease urokinase (u‐PA). To isolate peptides that block the interaction between PAI‐1 and u‐PA, phages bound to immobilized PAI‐1 were eluted by incubation with u‐PA. Remarkably, this procedure resulted in elution of a unique phage type that harbors a concatemer of decapentamers, consisting of 49 amino acid residues with no obvious similarity to the primary sequence of PAI‐1 or u‐PA.</jats:p>