Alteration of Fc-fusion protein serum half-lives by mutagenesis
AssigneePDL BioPharma, Inc.
InventorsPaul R. Hinton, Naoya Tsurushita
Life of this patent
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Abstract
The present invention provides for a modified Fc-fusion protein in which at least one amino acid from the heavy chain constant region selected from the group consisting of amino acid residues 250, 314, and 428 is substituted with another amino acid which is different from that present in the unmodified Fc-fusion protein, thereby altering the binding affinity for FcRn and/or the serum half-life in comparison to the unmodified Fc-fusion protein.
Claims15
A modified Fc-fusion protein comprising amino acid residues 250 and 428 that differ from the residues present in an unmodified Fc-fusion protein by amino acid residue 250 being glutamic acid or glutamine and amino acid residue 428 being leucine or phenylalanine, and wherein amino acid residues are numbered by the EU numbering system, and the Fc region of the modified Fc-fusion protein is of IgG isotype.
An Fc-fusion protein comprising an Fc region of a naturally occurring class IgG antibody, provided that amino acid residues 250 and 428 differ from the residues present in an unmodified Fc-fusion protein by amino acid residue 250 being glutamic acid or glutamine and amino acid residue 428 being leucine or phenylalanine, and wherein amino acid residues are numbered by the EU numbering system.
A method for altering FcRn binding affinity and/or serum half-life of an Fc-fusion protein, said method comprising selecting amino acid residues 250 and 428 present in the Fc region of an Fc-fusion protein, and substituting amino acid residue 250 with glutamic acid or glutamine and amino acid residue 428 with leucine or phenylalanine, and wherein the amino acid residues are numbered by the EU numbering system and the Fc region is of IgG isotype.
A method of producing a modified Fc-fusion protein with an altered binding affinity for FcRn and/or an altered serum half-life as compared with the unmodified Fc-fusion protein, said method comprising:
- (a) preparing an expression vector comprising a suitable promoter operably linked to DNA encoding at least an Fc region of an IgG heavy chain comprising amino acid residues 250 and 428 that are substituted with glutamic acid or glutamine at amino acid residue 250 and leucine or phenylalanine at amino acid residue 428, wherein the amino acid residues are numbered by the EU numbering system;
- (b) transforming host cells with said vector;
- and
- (c) culturing said transformed host cells to produce said modified Fc-fusion protein.
Dependencies are inferred from the claim text.