Autotransporters are the largest family of outer membrane/secreted proteins in Gram-negative bacteria. Many autotransporters are virulence factors which contribute to the pathogenesis of bacteria responsible for infectious diseases such as urinary tract infections, diarrhoea, whooping cough, meningitis and sepsis. These secreted proteins can be broadly divided in two groups, adhesins and proteases, which aid in establishing infections and contributing to disease by mediating host colonisation, cell invasion, biofilm formation and cytotoxicity. We have expressed and purified multi-milligram quantities of autotransporters belonging to different classes with the aim to characterise their unique structural properties that determine their specific function in pathogenesis. In addition, we are using antibody-based strategies to inhibit the activity of these proteins with aims to develop novel therapies targeting bacterial virulence.