Methods for Fragment Hit Follow-Up

In some cases, it is possible to observe ligand-protein complexes of fragment libraries by electrospray ionization mass spectrometry. This method was used to identify novel hits that functionally inhibit bacterial protein synthesis by binding to a subdomain of the 23S rRNA subunit. 

SPR is used to monitor the concentration of proteins at the surface of a solid support by measuring changes in refractive index. Libraries of functionalized fragments differing by virtue of the spacer length and composition as well as the linker functionality itself have been conjugated to solid support, followed by exposure to target proteins of interest. 

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