The present invention relates to the use of at least one compound comprising the amino acid sequence (Formula 1)(SEQ ID NO: 57) (X1)nX2X3PVX4X5X6(X7)m, wherein X1 is any amino acid residue, X2 is an amino acid residue selected from the group consisting of aspartic acid (D) and glutamic acid (E), X3 is any amino acid residue, X4 is any amino acid residue, X5 is an amino acid residue selected from the group consisting of proline (P) and alanine (A), X6 is an amino acid residue selected from the group consisting of aspartic acid (D) and glutamic acid (E), X7 is any amino acid residue, n and m, independently, are 0 or an integer of more than 0, and wherein the amino acid sequence according to Formula I is not identical with, or does not comprise the 8-mer polypeptide fragment of alpha-synuclein having the amino acid sequence DMPVDPDN (SEQ ID NO: 1), said compound having a binding capacity to an antibody which is specific for an epitope of alpha-synuclein comprising the amino acid sequence DMPVDPDN (SEQ ID NO: 1) for producing a medicament for preventing and/or treating synucleinopathies.