Download MendeleyThe price of flexibility - a case study on septanoses as pyranose mimetics.
Sager, C.P., Fiege, B., Zihlmann, P., Vannam, R., Rabbani, S., Jakob, R.P., Preston, R.C., Zalewski, A., Maier, T., Peczuh, M.W., Ernst, B.(2018) Chem Sci 9: 646-654
- PubMed: 29629131
- DOI: https://doi.org/10.1039/c7sc04289b
- Primary Citation of Related Structures:
5CGB - PubMed Abstract:
Seven-membered ring mimetics of mannose were studied as ligands for the mannose-specific bacterial lectin FimH, which plays an essential role in the first step of urinary tract infections (UTI). A competitive binding assay and isothermal titration calorimetry (ITC) experiments indicated an approximately ten-fold lower affinity for the seven-membered ring mannose mimetic 2- O-n -heptyl-1,6-anhydro-d- glycero -d-galactitol ( 7 ) compared to n -heptyl α-d-mannopyranoside ( 2 ), resulting exclusively from a loss of conformational entropy. Investigations by solution NMR, X-ray crystallography, and molecular modeling revealed that 7 establishes a superimposable H-bond network compared to mannoside 2 , but at the price of a high entropic penalty due to the loss of its pronounced conformational flexibility. These results underscore the importance of having access to the complete thermodynamic profile of a molecular interaction to "rescue" ligands from entropic penalties with an otherwise perfect fit to the protein binding site.
Organizational Affiliation:
University of Basel , Institute of Molecular Pharmacy , Pharmacenter of the University of Basel , Klingelbergstrasse 50 , 4056 , Basel , Switzerland . Email: beat.ernst@unibas.ch.
