Abstract: Compound capable of binding to gamma-interferon (?-IFN), chosen from the molecules corresponding to formula (I) below: in which X is a divalent spacer group that is sufficiently long to allow the two oligosaccharide fragments A and B to each bind to one of the peptide sequences 125 to 143 of the C-terminal ends of a ?-interferon (?-IFN) homodimer, n represents an integer from 0 to 10, and for example equal to 0, 1, 2, 3, 4 or 5, and each R independently represents a hydrogen atom, an SO3? group or a phosphate group, on the condition that no SO3? group is in the 3-position of the glucosamine units of compound (I). The invention also relates to the process for preparing these compounds, to the complexes formed by these compounds and gamma-interferon, and to the medicaments comprising these compounds or complexes.