Multi-domain proteins with increased native state colloidal stability
The present invention provides a method for generation of multi-domain proteins, more particular antibodies, with an improved native state colloidal stability. The present disclosure provides a method of producing an IgG1 or IgG4 antibody with an improved colloidal stability comprising, in embodiments: calculating for each domain of said IgG1 or IgG4 antibody the total net charge at a given pH; introducing one or more modifications to the amino acid residues of the constant region of said IgG1 or IgG4 antibody to minimize the charge sign difference between the domains, wherein said one or more modification is, or each are, a substitution of a charged amino acid by a polar (non-charged) amino acid; and producing the modified multi-domain protein with improved colloidal stability at the given pH.
1. A method of producing an IgG4 antibody with an improved colloidal stability comprising:
calculating for each domain of said IgG4 antibody the total net charge at a given pH;
modifying the DNA sequence encoding the IgG4 antibody to introduce one or more modifications to the amino acid residues of the constant region of said IgG 4 antibody to minimize the charge sign difference between the domains, wherein said one or more modification is, or each are, a substitution of a charged amino acid by a polar, non-charged amino acid, wherein said one or more modifications is, or are, selected from the list consisting of residues at positions R133, E137, D203, R214, E356, R409, E419 of Fc domain; and
producing the IgG4 antibody with improved colloidal stability at the given pH.
2. The method of claim 1 additionally comprising:
calculating the hydrophobicity of the domains of said IgG4 antibody;
modifying the DNA sequence encoding the IgG4 antibody to introduce one or more modifications to the hydrophobic residues to decrease the hydrophobicity of the domains; or
calculating for each domain of said IgG4 antibody of interest the number of unpaired charged amino acid residues.
3. The method of claim 1 , wherein the one or more modifications: minimize the number of charged residues.
4. The method of claim 1 , wherein the total net charge at a given pH is calculated by identifying opposite charged residues in the accessible surface area, and wherein the opposite charged residues located within a distance of less than 8 Å from each other are not taken into the determination of the total charge.
5. The method of claim 4 , wherein said distance is less than 5 Å.
6. The method of claim 5 , wherein the total net charge is the sum of unpaired charged residues.
7. The method of claim 1 , wherein said IgG4 antibody is produced using an expression vector.
8. The method of claim 1 , wherein colloidal stability is measured using a PEG induced precipitation assay.
9. The method of claim 1 , wherein one or more of the domains are not modified.
10. A method of producing an IgG1 or IgG4 antibody with an improved colloidal stability comprising:
calculating for each domain of said IgG1 or IgG4 antibody the total net charge at a given pH;
modifying the DNA sequence encoding the IgG1 or IgG4 antibody to introduce one or more modifications to the amino acid residues of the constant region of said IgG1 or IgG4 antibody to minimize the charge sign difference between the domains, wherein said one or more modification is, or each are, a substitution of a charged amino acid by a polar, non-charged amino acid;
modifying the DNA sequence encoding the IgG1 or IgG4 antibody to substitute one or more amino acids at positions 12, 18, 24, 39, 42, 45, 56 and 67 of the light chain and positions 13, 19, 64, 70, 75 and 83 of the heavy chain according to Kabat numbering by another amino acid to remove a positive charge or introduce a negative charge to minimize the charge sign difference between the domains of said IgG1 or IgG4 antibody; and
producing the IgG1 or IgG4 antibody with an improved colloidal stability at the given pH.
11. The method of claim 10 additionally comprising:
calculating the hydrophobicity of the domains of said IgG4 antibody;
modifying the DNA sequence encoding the IgG1 or IgG4 antibody to introduce one or more modifications to the hydrophobic residues to decrease the hydrophobicity of the domains; or calculating for each domain of said IgG4 antibody of interest the number of unpaired charged amino acid residues.
12. The method of claim 10 , wherein the one or more modifications: minimize the number of charged residues.
13. The method of claim 10 , wherein the total net charge at a given pH is calculated by identifying charged residues in the accessible surface area, and wherein the opposite charged residues located within a distance of less than 8 Å from each other are not taken into the determination of the total charge.
14. The method of claim 13 , wherein said distance is less than 5 Å.
15. The method of claim 14 , wherein the total net charge is the sum of unpaired charged residues.
16. The method of claim 10 , wherein said IgG1 or IgG4 antibody is produced using an expression vector.
17. The method of claim 10 , wherein colloidal stability is measured using a PEG induced precipitation assay.
18. The method of claim 10 , wherein one or more of the domains are not modified.