HIV-1 envelope trimer has similar binding characteristics for carbohydrate-binding agents as monomeric gp120.

The native HIV-1 Env complex consists of a gp120/gp41 trimer, but surface plasmon resonance (SPR)-directed binding studies for gp120-binding agents were almost exclusively performed on monomeric gp120. SPR-directed binding kinetics of monomeric gp120 and trimeric gp140 were investigated for a broad variety of envelope (Env)-binding agents. Similar kinetics for carbohydrate-binding agents (CBAs), the antibody 2G12 and sCD4 were observed, irrespective of the oligomeric state of gp120 that either contain the native mixture of complex and high-mannose N-glycans or that contain exclusively oligomannose N-glycans. The generally comparable kinetic properties of CBA, 2G12 and sCD4 binding to monomeric gp120 and trimeric gp140 indicate that monomeric gp120 is a good surrogate molecule for native HIV-1 Env trimer to investigate the binding affinities of Env-binding compounds.