Multivalent glycan engagement for antiviral functions. The overall dependence of lectin antiviral activity has previously been reported to be dependent on multivalent interactions which suggest cross-linking of oligosaccharides. Previously reported studies on the lectin GRFT with HIV-1 showed that obligate monomeric GRFT was ~1000-fold less active than dimeric GRFT, suggesting the need for multiple oligosaccharide engagement and was further investigated by studies of flexible GRFT tandemers which showed that increasing distances and flexibility between GRFT binding faces could improve anti-HIV activity while simultaneously decreasing viral aggregation .