A 45-Amino-Acid Scaffold Mined from the PDB for High-Affinity Ligand Engineering.

摘要: Small protein ligands can provide superior physiological distribution compared with antibodies, and improved stability, production, specific conjugation. Systematic evaluation of the PDB identified a scaffold to push limits small size robust evolution stable, high-affinity ligands: 45-residue T7 phage gene 2 (Gp2) contains an α helix opposite β sheet two adjacent loops amenable mutation. De novo ligand discovery from 10(8) mutants directed toward four targets yielded target-specific binders affinities as strong 200 ± 100 pM, Tms 65 °C 3 80°C 1 °C, retained activity after thermal denaturation. For cancer targeting, Gp2 domain for epidermal growth factor receptor was evolved 18 8 nM affinity, receptor-specific binding, high stability refolding. The efficiency evolving new binding function size, specificity, domains render uniquely effective scaffold.