Use of a catalytic peptide to catalyze a hydrolysis reaction, wherein the catalytic peptide consists of: at least one peptide selected from the group consisting of the following peptides (A1) to (C1): (A1) a peptide consisting of Box A and at least one of an upstream region or a downstream region therefrom in a Tob/BTG protein, wherein the peptide (A1) is a peptide consisting of an amino acid sequence of SEQ ID NO: 2; (A2) a peptide consisting of a partial region of the peptide (A1), wherein the peptide (A2) is a peptide consisting of an amino acid sequence of any one of SEQ ID NOs: 4 to 9, 11, 13, 57, and 58; (A3) a peptide that consists of an amino acid sequence obtained by deletion, substitution, addition, and/or insertion of one or more amino acids in an amino acid sequence of the peptide (A1) or (A2) and has hydrolysis activity, wherein the peptide (A3) is a peptide consisting of i) an amino acid sequence of any one of SEQ ID NOs: 16, 17, 20, 22 to 26, 50, 53, 54, and 55; or ii) an amino acid sequence of any one of SEQ ID NOs: 27 to 31, in SEQ ID NO: 27, Xaa is W, L, V, N, or D, in SEQ ID NO: 28, Xaa is K, V, Y, or M, in SEQ ID NO: 29, Xaa is T, E, P, or K, in SEQ ID NO: 30, Xaa is H, V, Y, Q, N, K, or G, and in SEQ ID NO: 31, Xaa is T, Q, V, K, or E; (B2) a peptide consisting of a partial region of Box B in the Tob/BTG protein, wherein the peptide (B2) is a peptide consisting of an amino acid sequence of any one of SEQ ID NOs: 36 or 37; (C1) a peptide consisting of a C-terminal region or an intermediate region in the Tob/BTG protein, wherein the peptide (C1) is a peptide consisting of an amino acid sequence of SEQ ID NO: 40. (A1) a peptide consisting of Box A and at least one of an upstream region or a downstream region therefrom in a Tob/BTG protein, wherein the peptide (A1) is a peptide consisting of an amino acid sequence of SEQ ID NO: 2; (A2) a peptide consisting of a partial region of the peptide (A1), wherein the peptide (A2) is a peptide consisting of an amino acid sequence of any one of SEQ ID NOs: 4 to 9, 11, 13, 57, and 58; (A3) a peptide that consists of an amino acid sequence obtained by deletion, substitution, addition, and/or insertion of one or more amino acids in an amino acid sequence of the peptide (A1) or (A2) and has hydrolysis activity, wherein the peptide (A3) is a peptide consisting of i) an amino acid sequence of any one of SEQ ID NOs: 16, 17, 20, 22 to 26, 50, 53, 54, and 55; or ii) an amino acid sequence of any one of SEQ ID NOs: 27 to 31, in SEQ ID NO: 27, Xaa is W, L, V, N, or D, in SEQ ID NO: 28, Xaa is K, V, Y, or M, in SEQ ID NO: 29, Xaa is T, E, P, or K, in SEQ ID NO: 30, Xaa is H, V, Y, Q, N, K, or G, and in SEQ ID NO: 31, Xaa is T, Q, V, K, or E; i) an amino acid sequence of any one of SEQ ID NOs: 16, 17, 20, 22 to 26, 50, 53, 54, and 55; or ii) an amino acid sequence of any one of SEQ ID NOs: 27 to 31, in SEQ ID NO: 27, Xaa is W, L, V, N, or D, in SEQ ID NO: 28, Xaa is K, V, Y, or M, in SEQ ID NO: 29, Xaa is T, E, P, or K, in SEQ ID NO: 30, Xaa is H, V, Y, Q, N, K, or G, and in SEQ ID NO: 31, Xaa is T, Q, V, K, or E; in SEQ ID NO: 27, Xaa is W, L, V, N, or D, in SEQ ID NO: 28, Xaa is K, V, Y, or M, in SEQ ID NO: 29, Xaa is T, E, P, or K, in SEQ ID NO: 30, Xaa is H, V, Y, Q, N, K, or G, and in SEQ ID NO: 31, Xaa is T, Q, V, K, or E; (B2) a peptide consisting of a partial region of Box B in the Tob/BTG protein, wherein the peptide (B2) is a peptide consisting of an amino acid sequence of any one of SEQ ID NOs: 36 or 37; (C1) a peptide consisting of a C-terminal region or an intermediate region in the Tob/BTG protein, wherein the peptide (C1) is a peptide consisting of an amino acid sequence of SEQ ID NO: 40. <EOS>