Ge Healthcare Bio-sciences Ab

Cytiva Bioprocess R&d Ab

Affibody Ab

Ge Healthcare Bio-sciences Corp.

Ge Healthcare Bioprocess R&d Ab

Ge Health Bio-sciences Ab

Sophia Hober

Hans J Johansson

Tomas Bjorkman

Elin Gunneriusson

Caroline Ekblad

Mathias Uhl&eacute;n

Amelie Eriksson Karlström

Anna Konrad

Sarah Lindbo

Johan Nilvebrant

Sara Kanje

The present invention is within the field of protein engineering and purification. The invention relates to a target-binding polypeptide mutant of an IgG binding polypeptide, such as Protein A, Protein G, Protein L or Protein M, comprising a metal binding motif. More closely the invention relates to an Fc binding ligand comprising an engineered protein based on the Protein A derived Z domain, to which a calcium binding EF-loop has been introduced.

Ligand and use thereof

The disclosure provides a population of polypeptide variants based on a common scaffold, each polypeptide in the population comprising the scaffold amino acid sequence XAELDXXGVG AXXIKXIXXA XXVEXVQXXK QXILAX. The disclosure also provides methods for selecting and identifying polypeptides from the population, as well as such polypeptides themselves.

Polypeptides based on a scaffold

The present invention relates to an immunoglobulin-binding protein, wherein at least one asparagine residue has been mutated to an amino acid other than glutamine or aspartic acid, which mutation confers an increased chemical stability at pH-values of up to about 13-14 compared to the parental molecule. The protein can for example be derived from a protein capable of binding to other regions of the immunoglobulin molecule than the complementarity determining regions (CDR), such as protein A, and preferably the B-domain of Staphylococcal protein A. The invention also relates to a matrix for affinity separation, which comprises an immunoglobulin-binding protein as ligand coupled to a solid support, in which protein ligand at least one asparagine residue has been mutated to an amino acid other than glutamine.

Mutated immunoglobulin-binding protein

Mutant protein

The present invention relates to site-specific labeling of antibodies or fragments thereof with one or more reporter group(s) in a way that does not affect antigen binding. The method for labeling antibodies and/or fragments thereof, comprises the following steps a) providing an IgG binding protein, which comprises &#x3b1;-helix structures, with a photoactivatable group and at least one label; b) forming a mixture of said IgG binding protein and the antibodies and/or fragments to be labeled; and c) UV illuminating said mixture for site-specific labeling of said antibodies and/or fragments thereof. The IgG binding protein is preferably the Z domain of Protein A.

Method for labeling of compounds

The present invention relates to the use of an alkali-stable protein, wherein at least one asparagine residue has been mutated to an amino acid other than glutamine or aspartic acid, which mutation confers an increased chemical stability at pH-values of up to about 13-14 compared to the parental molecule. The protein can for example be derived from a protein capable of binding to other regions of the immunoglobulin molecule than the complementarity determining regions (CDR), such as protein A, and preferably the B-domain of Staphylococcal protein A. The invention also relates to a matrix for affinity separation, which comprises an immunoglobulin-binding protein as ligand coupled to a solid support, in which protein ligand at least one asparagine residue has been mutated to an amino acid other than glutamine.

Protein ligands

Methods of affinity separation wherein the affinity ligand is an immobilized proteinaceous ligand wherein one or more of its asparagine (Asn) residues has been modified. Methods of making a stabilized combinatorial protein by a) modification of Asn residues within a protein molecule to increase stability of the protein in alkaline conditions, and b) randomization of a protein molecule to modify its binding characteristics, and combinatorial proteins wherein in a step separate from the randomization step, the stability of the protein in alkaline conditions has been increased by modifying one or more of its Asn residues.

Method of affinity separation and ligands for use therein

Growing community of inventors

Stockholm, Sweden

Sophia Hober