Phage displaying system expressing single chain antibody

A method for producing a disulfide-stabilized single chain antibody, comprising

• providing a host cell containing an expression construct, and
• culturing the host cell in a medium under conditions allowing expression of the disulfide-stabilized single chain antibody,
• wherein the expression construct includes a first nucleotide sequence encoding a signal peptide, and a second nucleotide sequence encoding a single chain antibody capable of forming an interface disulfide bond, the second nucleotide sequence being located 3′ downstream to the first nucleotide, and
• wherein the signal peptide has the amino acid sequence of
• VKKLLX1X2X3X4X5X6X7X8X9X10AAQPAMAHHHHHHGH (SEQ ID NO:596), in which X1 is A, C, F, G, I, L, M, P, Q, S, V, W, or Y;
• X2 is A, D, F, G, H, I, L, M, N, P, S, T, V, or W;
• X3 is A, F, G, L, M, P, Q, R, S, T, V, or W;
• X4 is A, F, G, H, I, L, M, P, Q, R, S, T, V, W, or Y;
• X5 is A, C, D, F, G, H, I, L, M, P, Q, R, S, T, V, W, or Y;
• X6 is A, C, D, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W, or Y;
• X7 is A, C, D, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W, or Y;
• X8 is A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W, or Y;
• X9 is A, C, D, E, F, G, H, I, L, M, N, P, Q, R, S, T, V, W, or Y;
• and X10 is A, C, D, E, F, G, H, I, K, L, M, N, P, Q, R, S, T, V, W, or Y.