Sedimentation equilibrium analysis of recombinant mouse FcRn with murine IgG1.
The interaction of mouse IgG1 or IgG1-derived Fc fragment with recombinant, insect cell expressed mouse FcRn has been analyzed using sedimentation equilibrium. This results in a model for the interaction in which the two binding sites for FcRn on Fc or IgG1 have significantly different affinities with macroscopic binding constants of < 130 nM and 6 microM. This data indicates the formation of an asymmetric FcRn:Fc (or IgG1):FcRn complex which is consistent with earlier suggestions that for this form of recombinant FcRn, binding to IgG1 or Fc does not result in a symmetric 2:1 complex in which both binding sites are equivalent.
Schuck
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Molecular Interactions Resource ORS, Bioengineering and Physical Science Program, National Institutes of Health, Bethesda, MD 20892-5766, USA.
Radu
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Ward
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D000818:Animals; D000915:Antibody Affinity; D001665:Binding Sites; D015395:Histocompatibility Antigens Class I; D007141:Immunoglobulin Fc Fragments / Q000302:isolation & purification / Q000378:metabolism; D007074:Immunoglobulin G / Q000302:isolation & purification / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D051379:Mice; D011961:Receptors, Fc / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D014461:Ultracentrifugation
D015395:Histocompatibility Antigens Class I; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D011961:Receptors, Fc; D011994:Recombinant Proteins; C100688:Fc receptor, neonatal