title: pH-sensitive interactions between IgG and a mutated IgG-binding protein based upon two B domains of protein A from Staphylococcus aureus.
abstract: A fusion protein, consisting of the N-terminal 81 amino acids from an inactive bovine DNase I (Q38,E39-E38,Q39) and two sequential synthetic IgG-binding domains based upon domain B of Protein A from Staphylococcus aureus has been shown to bind to porcine IgG with a similar affinity and pH profile to Protein A. The same residue in each B domain (Tyr111 and Tyr169) has been mutated by cassette mutagenesis to Ser, Glu, His, Lys or Arg and the effect of the mutation on binding interactions with porcine IgG investigated. The evidence presented suggests that the interactions at the B domain are highly sensitive to the presence of a charged residue.
authors.affiliation: Department of Biochemistry, School of Biological Sciences, University of Southampton, UK.
authors.forename: M G
authors.initials: MG
authors.lastname: Gore
authors.forename: W F
authors.initials: WF
authors.lastname: Ferris
authors.forename: A G
authors.initials: AG
authors.lastname: Popplewell
authors.forename: M
authors.initials: M
authors.lastname: Scawen
authors.forename: T
authors.initials: T
authors.lastname: Atkinson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D007074:Immunoglobulin G / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D013205:Staphylococcal Protein A / Q000235:genetics / Q000378:metabolism*; D013552:Swine / Q000276:immunology; D014443:Tyrosine
chemical_list: D007074:Immunoglobulin G; D011993:Recombinant Fusion Proteins; D013205:Staphylococcal Protein A; D014443:Tyrosine