Cell wall target fragment discovery using a low-cost, minimal fragment library

Fragment-based inhibitor design is an established and widely used approach in drug discovery pipelines. Despite several examples of drugs originating from this approach, the identification of fragments still suffers from issues with solubility, reactivity, cost and worldwide accessibility. Here, we design a low-cost minimal fragment library (LoCoFrag100) for crystallographic screening, with an average cLogP of 0.03 (median 0.23) and an average of £20/g for each compound, facilitating assembly in any laboratory. Formatted in a 10 × 10 matrix to minimize Tanimoto similarity in the 20 cocktails, we demonstrate its applicability on three structurally distinct enzymes involved in microbial cell wall synthesis. Hit rates range from 1 to 6% among these enzymes, with three fragments suggesting avenues for inhibitor exploration. Impact Statement LoCoFrag100 is a low-cost, easily accessible fragment library that enables rapid survey of target ligandability in any laboratory, providing evidence to prioritise targets for follow-up research.