Method for preparing Fc containing polypeptides having improved properties

1. An Fc-containing polypeptide comprising mutations at amino acid positions 243, 264, 267 and 328 of the Fc region, wherein the numbering is according to the EU index as in Kabat wherein the mutations are F243A, V264A, S267E, and L328F, and wherein the Fc region in the Fc-containing polypeptide is from an IgG.

2. The Fc-containing polypeptide of claim 1 , comprising the amino acid sequence of SEQ ID NO:7, SEQ ID NO:8, or SEQ ID NO:17.

3. The Fc-containing polypeptide of claim 1 , wherein said Fc-containing polypeptide is an antibody or an antibody fragment comprising sialylated N-glycans, wherein the sialic acid residues in the sialylated N-glycans are attached via α-2,6 linkages.

4. The Fc-containing polypeptide of claim 1 , wherein said Fc-containing polypeptide is an antibody or an antibody fragment comprising sialylated N-glycans comprising a structure selected from SA (1-4) Gal (1-4) GlcNAc (2-4) Man 3 GlcNAc 2 or SAGalGlcNAcMan 5 GlcNAc 2 , wherein the sialic acid residues are attached via α-2,6 linkages.

5. The Fc-containing polypeptide of claim 1 , wherein said Fc-containing polypeptide has one or more of the following properties when compared to a parent Fc-containing polypeptide:

a) reduced effector function;

b) increased anti-inflammatory properties;

c) increased binding to a lectin;

d) reduced binding to FcγRIIa;

e) increased binding to FcγRIIb;

f) reduced binding to FcγRIIIa;

g) reduced binding to FcγRIIIb.