However, it is to be understood that any amino acid sequence that comprises the binding motif Q/E- (x) 3 -x p , wherein x p is a hydrophobic amino acid residue and (x) 3 is an amino acid sequence of three amino acid resides, wherein x is any amino acid residue, or the binding motif K/R-x p -(x) 0- rK/R, wherein x p is a hydrophobic amino acid residue and (x) is a charged amino acid residue, may be