METHODS AND COMPOSITIONS FOR PREVENTING NORLEUCINE MISINCORPORATION INTO PROTEINS Russian patent published in 2019 - IPC C12P21/02 

FIELD: biotechnology.

SUBSTANCE: disclosed are E.coli host cells for obtaining an anti-VEGF antibody or antigen-binding fragment of anti-VEGF, free from norleucine misincorporation, E.coli host cell for obtaining an antibody against factor D or an antigen-binding fragment against factor D, free from norleucine misincorporation, and E.coli host cell for obtaining an anti-MET antibody or antigen-binding fragment of an anti-MET, free from norleucine misincorporation. Host cell comprises a mutant metA allele, comprising a nucleic acid sequence encoding an amino acid substitution in MetA, selected from the group consisting of arginine substitution with cysteine at amino acid position 27, glutamine substitution with glutamic acid at amino acid position 64, tyrosine substitution with cysteine at amino acid position 294, isoleucine substitution with serine at amino acid position 296, proline substitution with leucine at amino acid position 298; isoleucine substitution with serine at amino acid position 296; and proline substitution with leucine at amino acid position 298. Host cell further comprises a nucleic acid encoding a target protein. Also disclosed is a method for producing an anti-VEGF antibody or an antigen-binding fragment of an anti-VEGF, free from norleucine misincorporation, a method of producing an antibody against factor D or an antigen-binding fragment against factor D, free from norleucine misincorporation, and a method of producing an anti-MET antibody or antigen-binding fragment of an anti-MET, free from norleucine misincorporation, using the corresponding above-mentioned host cells.

EFFECT: invention is effective in preventing the incorporation of norleucine into proteins during production of a recombinant protein in bacteria.

16 cl, 23 dwg, 9 tbl, 7 ex