text: Avidin and biotinylated artificial metal cofactor the most commonly used supramolecular strategy to make an ArM. In the example showed below, the ligand of Ru(I) complex was modified with biotin and than the whole complex was loaded onto streptavidin by biotin-avidin interaction. The resulted ArM can catalyze the reduction of prochiral ketones. Taking advantages of protein context, different mutants of strepavidin can achieve different stereochemistry selectivity by direct evolution. For example, Mutant L124V can selectively reduce certain ketone into R-alcohol while S112A-K121N can reduce the same substance into S-alcohol.<nowiki/>
  Besides biotin-avidin based ArMs, another important attempt utilizing supuramolecular interaction is antigen-antibody recognition. First reported in 1989 by Lerner, a monoclonal antibody-based ArM is raised to hydrolyze specific peptide.