An isolated and purified protein or polypeptide having mucosa binding activity and a molecular weight of 20-40 kD as measured by non-gradient denaturing SDS-PAGE, using a calibration curve obtained with standard proteins, and gel filtration chromatography, relative to the standard curve, or a functionally equivalent polypeptide thereof having mucosa binding activity, wherein said protein or polypeptide comprises one or more of the following amino acid sequences:
- 2 I) AASAVNSELVHK (SEQ ID No. 21) II) ANFVPTK (SEQ ID No. 22) III) DTAIQSSYNK (SEQ ID No. 23) IV) ISALFNK (SEQ ID No. 24) V) IAGTGTNNA, (SEQ ID No. 25)
- and wherein said mucosa binding activity comprises binding to a receptor which is present on the mucosa .and is recognized by a pathogenic microorganism: