Patent ID: 7851592

Claim:
An isolated or recombinant polypeptide comprising the amino acid sequence: X 1 X 2 X 3 X 4 X 5 X 6 X 7 X 8 X 9 X 10 X 11 wherein X1 is L, F, W, M, R, I, V, Y, K, or absent, X2 is Y, F, A, W, S or T, X3 is R, S, G, T, or H, X4 is S, L, P or G, X5 is P, A, or G, X6 is S, A, N, H, G, or P, X7 is M, E, G, H, Q, Y, or F, X8 is P, L, G, F, W or Y, X9 is E, S, N, G, or absent, X10 is N, G, L, S, M, P, N, A, or absent, and X11 is L, M, or absent, wherein the amino acid sequence is selected from the group consisting of R Y S L P P E L S N M (SEQ ID NO: 1), L Y T S P S Y Y E N L (SEQ ID NO: 76), L Y H S P S Y Y E N L (SEQ ID NO: 108), L F T S P S Y Y E N L (SEQ ID NO: 300), W Y R S P S F Y E N L (SEQ ID NO: 904), W Y T S P S H P E N L (SEQ ID NO: 990), Y G G P G G G G N (SEQ ID NO: 1895), and L A R S A S M P E A L (SEQ ID NO: 1896), and wherein the polypeptide can be a phosphorylation substrate of a human Chk2 kinase in vitro.