Generation of enantiospecific monoclonal antibodies against (2R,6R)-hydroxynorketamine.
Bioorganic & medicinal chemistry January 17, 2026 Uriel Matthew Enriquez, Natalie M González Velázquez, Mohammad Mosharraf Hossain et al.
Monoclonal antibodies were developed that specifically recognize (2R,6R)-hydroxynorketamine, a metabolite of ketamine linked to rapid antidepressant effects. An immunogenic bioconjugate was designed by attaching a 6-aminohexanoic acid linker to the pharmacophore and coupling it to a carrier protein. Mice immunized with this conjugate produced equivalent antibody titers to a racemic comparator. Hybridoma screening yielded the monoclonal antibody 6F11-HC1-LC2, which showed strong binding to (2R,6R)-hydroxynorketamine but no response to the (2S,6S) enantiomer in competitive ELISA. Surface plasmon resonance revealed sub-nanomolar affinity (0.4 nM) for (2R,6R)-hydroxynorketamine-BSA conjugates and over 150-fold selectivity over ketamine-BSA conjugates. These antibodies can be used in future studies to investigate the roles of hydroxynorketamine enantiomers in ketamine's antidepressant effects.