Amyloid-beta-binding peptides and the use thereof for the treatment and diagnosis of Alzheimer's disease

1. A peptide comprising an amino acid sequence which binds to amyloid beta species,

wherein the peptide has been modified by cyclization,

wherein the amino acid sequence is selected from the group consisting of SEQ ID NO: 1, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11 and homologs thereof, with an identity of at least 80%, and

wherein the peptide's binding affinity to the amyloid beta species is increased as compared to an analogous peptide without any modification.

2. The peptide according to claim 1 , wherein D-enantiomeric amino acids make up at least 50% of the amino acid sequence.

3. The peptide according to claim 1 , being linked to a further substance.

4. The peptide according to claim 1 , comprising at least two amino acid sequences, one of which is SEQ ID NO: 1 and the other being selected from the group consisting of SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12 and homologs thereof.

5. The peptide according to claim 4 , wherein the at least two amino acid sequences together form a second amino acid sequence selected from the group consisting of SEQ ID NO: 4 and SEQ ID NO: 5, and homologs thereof.

6. A method for producing a peptide according to claim 1 , comprising a step of producing the peptide by way of peptide synthesis or mutagenesis.

7. A kit comprising a peptide according to claim 1 .

8. A composition comprising a peptide according to claim 1 .