Peptide compound of the following general formula: R 1 - n -X 1 -X 2 -X 3 -Lys-Lys-Gln-Lys-Trp-X 4 - p -R 2 wherein, X 1 represents an asparagine, a glycine, a threonine, an alanine or no amino acid, X 2 represents an isoleucine, a leucine, a methionine, a proline, or no amino acid, X 3 represents a threonine, an asparagine, a serine or no amino acid, X 4 represents a serine, a cysteine, a threonine, an asparagine, a glutamine or no amino acid, AA represents any amino acid, and n and p are integers between 0 and 2, R 1 represents the primary amine function of the N-terminal amino acid, -NH2, wherein one of the two hydrogen atoms may or may not be substituted either by an acetyl-type saturated or an unsaturated C 1 to C 30 alkyl chain, or by an aromatic group of the benzoyl, tosyl or benzyloxycarbonyl type, R 2 represents the hydroxyl group of the carboxyl function of the C-terminal amino acid, -OH, wherein the hydrogen atom may or may not be substituted either by a C 1 to C 30 alkyl chain, or an NH 2, NHY or NYY group, wherein Y represents a C 1 à C 4 alkyl chain, said sequence of general formula consisting of 5 to 13 amino acid residues, characterized in that it corresponds to one of the following formulas: (SEQ ID no. 1) Asn - Thr - Lys - Lys - Gln - Lys - Trp-Thr - Asn - NH 2 (SEQ ID no. 2) Lys - Lys - Gln - Lys - Trp - NH 2 (SEQ ID no. 3) Gly - Gly - Leu - Lys - Lys - Gln - Lys-Trp - Asn - Leu - Tyr (SEQ ID no. 4) Ala - Met - Lys - Lys - Gln - Lys - Trp - NH 2 (SEQ ID no. 5) Ala - Leu - Ser - Lys - Lys - Gln - Lys - Trp - Gln (SEQ ID no. 6) Cys - Lys - Lys - Gln - Lys - Trp - Ser - NH 2 X 1 represents an asparagine, a glycine, a threonine, an alanine or no amino acid, X 2 represents an isoleucine, a leucine, a methionine, a proline, or no amino acid, X 3 represents a threonine, an asparagine, a serine or no amino acid, X 4 represents a serine, a cysteine, a threonine, an asparagine, a glutamine or no amino acid, AA represents any amino acid, and n and p are integers between 0 and 2, R 1 represents the primary amine function of the N-terminal amino acid, -NH2, wherein one of the two hydrogen atoms may or may not be substituted either by an acetyl-type saturated or an unsaturated C 1 to C 30 alkyl chain, or by an aromatic group of the benzoyl, tosyl or benzyloxycarbonyl type, R 2 represents the hydroxyl group of the carboxyl function of the C-terminal amino acid, -OH, wherein the hydrogen atom may or may not be substituted either by a C 1 to C 30 alkyl chain, or an NH 2, NHY or NYY group, wherein Y represents a C 1 à C 4 alkyl chain, said sequence of general formula consisting of 5 to 13 amino acid residues, characterized in that it corresponds to one of the following formulas: (SEQ ID no. 1) Asn - Thr - Lys - Lys - Gln - Lys - Trp-Thr - Asn - NH 2 (SEQ ID no. 2) Lys - Lys - Gln - Lys - Trp - NH 2 (SEQ ID no. 3) Gly - Gly - Leu - Lys - Lys - Gln - Lys-Trp - Asn - Leu - Tyr (SEQ ID no. 4) Ala - Met - Lys - Lys - Gln - Lys - Trp - NH 2 (SEQ ID no. 5) Ala - Leu - Ser - Lys - Lys - Gln - Lys - Trp - Gln (SEQ ID no. 6) Cys - Lys - Lys - Gln - Lys - Trp - Ser - NH 2 (SEQ ID no. 1) Asn - Thr - Lys - Lys - Gln - Lys - Trp-Thr - Asn - NH 2 (SEQ ID no. 2) Lys - Lys - Gln - Lys - Trp - NH 2 (SEQ ID no. 3) Gly - Gly - Leu - Lys - Lys - Gln - Lys-Trp - Asn - Leu - Tyr (SEQ ID no. 4) Ala - Met - Lys - Lys - Gln - Lys - Trp - NH 2 (SEQ ID no. 5) Ala - Leu - Ser - Lys - Lys - Gln - Lys - Trp - Gln (SEQ ID no. 6) Cys - Lys - Lys - Gln - Lys - Trp - Ser - NH 2