Patent ID: 8629245

Claim:
A polypeptide comprising an aglycosylated variant human IgG Fc domain capable of binding an FcR polypeptide, wherein the variant Fc domain comprises an amino acid substitution of P331L, E382V, M428I or M428L, wherein the numbering of the residues in the Fc region is that of the EU index as in Kabat, and further wherein the Fc domain comprises a substitution selected from the group consisting of a) E382V and M428I; b) E382V; c) N361D, E382V and M428I; d) N361D, F372L, E382V and M428I; e) H310Y, K322R, T350A, E382V, S426T and S442P; f) C229R, E382V and M428I; g) W313R and M428I; h) E382T, N384D and M428I; i) E380R, E382M and N384E; j) N361S, E382V and M428I; k) E382V, M428I and Y436A; l) P238S, E382V, S426V, M428L and E430H; m) E380D, E382V, N384R, S426V, M428L and E430D; n) E382V, S426I, M428L and E430S; o) H224R, E382V, S426T, M428S and E430P; p) S239L, 1253T, Q347L, E382V; q) E382V, G402D and M428I; and r) E382V, P331L and M428I.