A peptide amounting in total 19 amino acid residues, wherein the peptide is selected from the group consisting of: Lys-Lys-Lys-Lys-Lys-Lys-Ser-Ser-Ile-Ile-Ser-His-Phe-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 13) Glu-Glu-Glu-Glu-Glu-Glu-Ser-Ser-Ile-Ile-Ser-His-Phe-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 14) Lys-Lys-Lys-Lys-Lys-Lys-Ser-Ser-Ile-Ile-Ser-His-Phe-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 15) Glu-Glu-Glu-Glu-Glu-Glu-Ser-Ser-Ile-Ile-Ser-His-Phe-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 16) Lys-Lys-Lys-Lys-Lys-Lys-Ser-Ser-Ile-Ile-Ser-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 17) Glu-Glu-Glu-Glu-Glu-Glu-Ser-Ser-Ile-Ile-Ser-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 18) Lys-Lys-Lys-Lys-Lys-Lys-Ser-Ser-Ile-Ile-Ser-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 19) Glu-Glu-Glu-Glu-Glu-Glu-Ser-Ser-Ile-Ile-Ser-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 20) Lys-Lys-Lys-Lys-Lys-Lys-Ser-Ser-Ile-Ile-Ser-His-D-Nal-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 21) Glu-Glu-Glu-Glu-Glu-Glu-Ser-Ser-Ile-Ile-Ser-His-D-Nal-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 22) Lys-Lys-Lys-Lys-Lys-Lys-Ser-Ser-Ile-Ile-Ser-His-D-Nal-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 23) Glu-Glu-Glu-Glu-Glu-Glu-Ser-Ser-Ile-Ile-Ser-His-D-Nal-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 24); or Amounting in total 16 amino acid residues, wherein the peptide is selected from the group consisting of: Lys-Lys-Lys-Lys-Lys-Lys-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 25) Glu-Glu-Glu-Glu-Glu-Glu-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 26) Lys-Lys-Lys-Lys-Lys-Lys-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 27) Glu-Glu-Glu-Glu-Glu-Glu-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 28) Lys-Lys-Lys-Lys-Lys-Lys-Nle-Glu-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 29) Glu-Glu-Glu-Glu-Glu-Glu-Nle-Glu-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 30), Lys-Lys-Lys-Lys-Lys-Lys-Nle-Glu-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 31) Glu-Glu-Glu-Glu-Glu-Glu-Nle-Glu-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 32) Lys-Lys-Lys-Lys-Lys-Lys-Nle-Glu-His-D-Nal-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 33) Glu-Glu-Glu-Glu-Glu-Glu-Nle-Glu-His-D-Nal-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 34) Lys-Lys-Lys-Lys-Lys-Lys-Nle-Glu-His-D-Nal-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 35), and Glu-Glu-Glu-Glu-Glu-Glu-Nle-Glu-His-D-Nal-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 36). Lys-Lys-Lys-Lys-Lys-Lys-Ser-Ser-Ile-Ile-Ser-His-Phe-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 13) Glu-Glu-Glu-Glu-Glu-Glu-Ser-Ser-Ile-Ile-Ser-His-Phe-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 14) Lys-Lys-Lys-Lys-Lys-Lys-Ser-Ser-Ile-Ile-Ser-His-Phe-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 15) Glu-Glu-Glu-Glu-Glu-Glu-Ser-Ser-Ile-Ile-Ser-His-Phe-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 16) Lys-Lys-Lys-Lys-Lys-Lys-Ser-Ser-Ile-Ile-Ser-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 17) Glu-Glu-Glu-Glu-Glu-Glu-Ser-Ser-Ile-Ile-Ser-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 18) Lys-Lys-Lys-Lys-Lys-Lys-Ser-Ser-Ile-Ile-Ser-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 19) Glu-Glu-Glu-Glu-Glu-Glu-Ser-Ser-Ile-Ile-Ser-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 20) Lys-Lys-Lys-Lys-Lys-Lys-Ser-Ser-Ile-Ile-Ser-His-D-Nal-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 21) Glu-Glu-Glu-Glu-Glu-Glu-Ser-Ser-Ile-Ile-Ser-His-D-Nal-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 22) Lys-Lys-Lys-Lys-Lys-Lys-Ser-Ser-Ile-Ile-Ser-His-D-Nal-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 23) Glu-Glu-Glu-Glu-Glu-Glu-Ser-Ser-Ile-Ile-Ser-His-D-Nal-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 24); or Lys-Lys-Lys-Lys-Lys-Lys-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 25) Glu-Glu-Glu-Glu-Glu-Glu-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 26) Lys-Lys-Lys-Lys-Lys-Lys-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 27) Glu-Glu-Glu-Glu-Glu-Glu-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 28) Lys-Lys-Lys-Lys-Lys-Lys-Nle-Glu-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 29) Glu-Glu-Glu-Glu-Glu-Glu-Nle-Glu-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 30), Lys-Lys-Lys-Lys-Lys-Lys-Nle-Glu-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 31) Glu-Glu-Glu-Glu-Glu-Glu-Nle-Glu-His-(D-Phe)-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 32) Lys-Lys-Lys-Lys-Lys-Lys-Nle-Glu-His-D-Nal-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 33) Glu-Glu-Glu-Glu-Glu-Glu-Nle-Glu-His-D-Nal-Arg-Trp-Gly-Lys-Pro-Val (SEQ ID NO: 34) Lys-Lys-Lys-Lys-Lys-Lys-Nle-Glu-His-D-Nal-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 35), and Glu-Glu-Glu-Glu-Glu-Glu-Nle-Glu-His-D-Nal-Arg-Trp-Gly-Lys-Pro-(D-Val) (SEQ ID NO: 36).