Patent ID: 7479372

Claim:
A method for assaying for decreased β-secretase activity comprising measuring a cleavage product produced from cleavage by β-secretase of β-amyloid precursor protein (APP) substrate comprising a β-secretase peptide substrate, comprising a β-secretase cleavage site and having the formula P4-P3-P2-P1-P1′-P2′-P3′-P4′, where P4 is selected from the group consisting of D, E, I, L and V; P3 is selected from the group consisting of L, I, V and N; P2 is selected from the group consisting of F, Y, E and N; P1 is selected from the group consisting of F, I, L and Y; P1′ is selected from the group consisting of A, E, S, I, L and D; P2′ is selected from the group consisting of V, I, L and A; P3′ is selected from the group consisting of V, I, L, E and Y; and P4′ is selected from the group consisting of P, W and F; where P4-P3-P2-P1-P1′-P2′-P3′-P4′ cannot simultaneously be chosen such that they comprise the Swedish mutation β-secretase cleavage site (SEQ ID NO: 257); and where a decrease in β-secretase activity is determined when the amount of the cleavage product is decreased relative to the amount of the cleavage product produced from an APP substrate having the Swedish mutation β-secretase cleavage site (SEQ ID No: 257).