Patent ID: 8129334

Claim:
An isolated polypeptide consisting essentially of a fragment of an N-terminal domain of a Presenilin-1 polypeptide, said domain having a sequence from amino acid x 1 to x 2 of SEQ ID NO:2, wherein x 1 is selected from amino acid 1, 2, 3, 4, and 5 of SEQ ID NO:2 and x 2 is selected from amino acid 79, 80, 81, 82 and 83 of SEQ ID NO:2 wherein the isolated polypeptide contains an amino acid sequence selected from the group consisting of: (i) DEEEDEEL (SEQ ID NO:5), (ii) SEQ ID NO:5 further including 1-50 additional amino acids at either the N- or C-terminal end wherein the polypeptide inhibits cell-cell interaction, inhibits Aβ production or binds to a β-APP, (iii) RRSLGHPEPLSNGRP (SEQ ID NO:6), (iv) SEQ ID NO:6 further including 1-5 conservative amino acid substitutions, wherein the polypeptide inhibits cell-cell interaction, inhibits Aβ production or binds to a β-APP, (v) a sequence of (iii) or (iv) further including 1-50 additional amino acids at the N- or C-terminus, wherein the polypeptide inhibits cell-cell interaction, inhibits Aβ production or binds to a β-APP, (vi) RRSLGHPEPLSNGRPQGNSRQVVEQDEEEDEELTLKYGAK (SEQ ID NO:7), (vii) SEQ ID NO:7 further including 1-5 conservative amino acid substitutions, wherein the polypeptide inhibits cell-cell interaction, inhibits Aβ production or binds to a β-APP, (viii) a sequence consisting of (vi) or (vii) further including 1-50 additional amino acids at the N- or C-terminus, wherein the polypeptide inhibits cell-cell interaction, inhibits Aβ production or binds to a β-APP, and (ix) any of the foregoing polypeptides comprising an unnatural amino acid or D-amino acid wherein the polypeptide inhibits cell-cell interaction, inhibits Aβ production or binds to a β-APP.