Here we report an approach to the design and production of antibody/ligand pairs, to achieve functional affinity far greater than avidin/biotin. Using fundamental chemical principles, we have developed antibody/ligand pairs that retain the binding specificity of the antibody, but do not dissociate. Choosing a structurally characterized antibody/ligand pair as an example, we engineered complemen...

Peptostreptococcus anaerobius converted glutamine stoichiometrically to ammonia and pyroglutamic acid, and the Eadie-Hofstee plot of glutamine transport was biphasic. High-affinity, sodium-dependent glutamine transport (affinity constant [Kt] of 1.5 microM) could be driven by the chemical gradient of sodium, and more than 20 mM sodium was required for half-maximal velocity. High-affinity glutam...