Engineering hydrophobic protein-carbohydrate interactions to fine-tune monoclonal antibodies.

ABSTRACT: Biologically active conformations of the IgG1 Fc homodimer are maintained by multiple hydrophobic interactions between the protein surface and the N-glycan. The Fc glycan modulates biological effector functions, including antibody-dependent cellular cytotoxicity (ADCC) which is mediated in part through the activatory Fc receptor, FcγRIIIA. Consistent with previous reports, we found that site-directed mutations disrupting the protein-carbohydrate interface (F241A, F243A, V262E, and V264E) increased galactosylation and sialylation of the Fc and, concomitantly, reduced the affinity for FcγRIIIA. We rationalized this effect by crystallographic analysis of the IgG1 Fc F241A mutant, determined here to a resolution of 1.9 Å, which revealed localized destabilization of this glycan-protein interfac

SUBMITTER: Yu X 

PROVIDER: S-EPMC3788586 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature