Method for improving thermal stability of antibody and method for producing modified antibody

1. A method for improving thermal stability of an antibody, comprising:

in a heavy chain of the antibody, changing at least one amino acid residue selected from the group consisting of 8th to 11th amino acid residues based on Kabat method to a cysteine residue, and changing at least one amino acid residue selected from the group consisting of 109th and 110th amino acid residues based on IMGT method to a cysteine residue,

wherein the modified antibody has improved thermal stability as compared to the unmodified antibody; and

wherein the modified antibody is Fab, Fab′, F(ab′)2, reduced IgG, IgG, IgA, IgM, IgD or IgE.

2. The method according to claim 1 , wherein the changing step comprises substituting the at least one amino acid residue selected from the group consisting of the 8th to 11th amino acid residues to a cysteine residue.

3. The method according to claim 1 , wherein the changing step comprises substituting the at least one amino acid residue selected from the group consisting of the 109th and 110th amino acid residues to a cysteine residue.

4. The method according to claim 1 , wherein the changing step comprises changing at least one amino acid residue selected from the group consisting of 9th and 10th amino acid residues based on the Kabat method to a cysteine residue.

5. The method according to claim 1 , wherein the changing step comprises substituting at least one amino acid residue selected from the group consisting of 9th and 10th amino acid residues based on the Kabat method to a cysteine residue.

6. The method according to claim 1 , wherein the changing step comprises changing amino acid residues selected from the group consisting of 1) to 3) below to cysteine residues,

1) The 9th amino acid residue based on the Kabat method and the 109th amino acid residue based on the IMGT method;

2) The 9th amino acid residue based on the Kabat method and the 110th amino acid residue based on the IMGT method; and

3) The 10th amino acid residue based on the Kabat method and the 110th amino acid residue based on the IMGT method.

7. The method according to claim 1 , wherein a disulfide bond is formed between the cysteine residue at any position of 8 to 11 based on the Kabat method and the cysteine residue at any position of 109 and 110 based on the IMGT method.

8. The method according to claim 1 , further comprising:

in a light chain of the antibody, changing 80th and 171st amino acid residues based on the Kabat method to cysteine residues.

9. The modified antibody according to claim 8 , wherein a disulfide bond is formed between the cysteine residues at positions 80 and 171 based on the Kabat method.

10. A method for producing a modified antibody, comprising:

in a heavy chain of the antibody, changing at least one amino acid residue selected from the group consisting of 8th to 11th amino acid residues based on Kabat method to a cysteine residue, and changing at least one amino acid residue selected from the group consisting of 109th and 110th amino acid residues based on IMGT method to a cysteine residue;

wherein a disulfide bond is formed between the cysteine residue at any position of 8 to 11 based on the Kabat method and the cysteine residue at any position of 109 and 110 based on the IMGT method;

wherein the modified antibody is Fab, Fab′, F(ab′)2, reduced IgG, IgG, IgA, IgM, IgD or IgE, and

recovering the modified antibody.

11. The method according to claim 10 , wherein the changing step comprises substituting the at least one amino acid residue selected from the group consisting of the 8th to 11th amino acid residues to a cysteine residue.

12. The method according to claim 10 , wherein the changing step comprises substituting the at least one amino acid residue selected from the group consisting of the 109th and 110th amino acid residues to a cysteine residue.

13. The method according to claim 10 , wherein the changing step comprises changing at least one amino acid residue selected from the group consisting of 9th and 10th amino acid residues based on the Kabat method to a cysteine residue.

14. The method according to claim 10 , wherein the changing step comprises substituting at least one amino acid residue selected from the group consisting of 9th and 10th amino acid residues based on the Kabat method to a cysteine residue.

15. The method according to claim 10 , wherein the changing step comprises changing amino acid residues selected from the group consisting of 1) to 3) below to cysteine residues,

1) The 9th amino acid residue based on the Kabat method and the 109th amino acid residue based on the IMGT method;

2) The 9th amino acid residue based on the Kabat method and the 110th amino acid residue based on the IMGT method; and

3) The 10th amino acid residue based on the Kabat method and the 110th amino acid residue based on the IMGT method.

16. The method according to claim 10 , further comprising: in a light chain of the antibody, changing 80th and 171st amino acid residues based on the Kabat method to cysteine residues.

17. The modified antibody according to claim 16 , wherein a disulfide bond is formed between the cysteine residues at positions 80 and 171 based on the Kabat method.