The effect of sugar removal on the structure of the Fc region of an IgG antibody as observed with single molecule Förster Resonance Energy Transfer.

•Single molecule FRET can be used to study the structure of the Fc region of IgG.•FRET results for glycosylated IgG agree with crystal structure results.•FRET results for deglycosylated IgG indicate a wide range of Fc conformations.•Deglycosylation appears to enhance the flexibility of the Fc region of IgG.