A Redesigned Vancomycin Engineered for Dual D-Ala-D-Ala and D-Ala-D-Lac Binding Exhibits Potent Antimicrobial Activity Against Vancomycin-Resistant Bacteria

摘要

The emergence of bacteria resistant to vancomycin, often the antibiotic of last resort, poses a major health problem. Vancomycin-resistant bacteria sense a glycopeptide antibiotic challenge and remodel their cell wall precursor peptidoglycan terminus from D-Ala-d-Ala to D-Ala-D-Lac, reducing the binding of vancomycin to its target 1000-fold and accounting for the loss in antimicrobial activity. Here, we report [Φ[C(=NH)NH]Tpg⁴]-vancomycin aglycon designed to exhibit the dual binding to D-Ala-D-Ala and D-Ala-D-Lac needed to reinstate activity against vancomycin-resistant bacteria. Its binding to a model D-Ala-D-Ala ligand was found to be only two-fold less than vancomycin aglycon and this affinity was maintained with a model D-Ala-D-Lac ligand, representing a 600-fold increase relative to vancomycin aglycon. Accurately reflecting these binding characteristics, it exhibits potent antimicrobial activity against vancomycin-resistant bacteria (MIC = 0.31 g/mL, VanA VRE). Thus, a complementary single atom exchange in the vancomycin core structure (O NH) to counter the single atom exchange in the cell wall precursors of resistant bacteria (NH O) reinstates potent antimicrobial activity and charts a rational path forward for the development of antibiotics for the treatment of vancomycin-resistant bacterial infections.