A novel von Willebrand factor binding protein expressed by Staphylococcus aureus

Department of Microbiology, Swedish University of Agricultural Sciences, Box 7025, SE-75007 Uppsala, Sweden 1 Department of Infectious Diseases and Medical Microbiology, Lund University, Sölvegatan 23, SE-22362 Lund, Sweden 2 Department of Microbiology, Pathology and Immunology, Huddinge University Hospital, Karolinska Institutet, SE-14186 Huddinge, Sweden 3 Author for correspondence: Lars Frykberg. Tel: +46 18673299. Fax: +46 18673392. e-mail: Lars.Frykberg{at}mikrob.slu.se When a shotgun phage-display library of Staphylococcus aureus Newman was affinity selected (panned) against recombinant von Willebrand factor (vWf), a novel von Willebrand factor binding protein (vWbp) was found. Experimental data indicate that the interaction between vWbp and vWf is very specific and mediated by a region of 26 aa residues in the C-terminal part of vWbp. vWbp has an N-terminal secretory signal sequence but no cell wall anchoring motif, suggesting a soluble extracellular location. Mature vWbp could be purified from the culture supernatant and the identity of the protein was confirmed by N-terminal sequencing. vWbp migrates with an apparent molecular mass of 66 kDa and the deduced protein consists of 482 aa. The gene encoding vWbp, named vwb , was present in all S. aureus strains investigated. Keywords: receptin, virulence factor, phage display Abbreviations: HSA, human serum albumin; HRP, horseradish peroxidase; RT, room temperature; vWf, von Willebrand factor; vWbp, von Willebrand factor binding protein a The GenBank accession number for the sequence reported in this paper is AY032850 .