Directed evolution is a method of protein engineering where the sequential rounds of mutagenesis and selection or screening are used modify protein function to a desired end-point. In the case of enzymes, this could be improve activity or to expand substrate scope. Recent work in the McLeod group have engineered to Pseudomonas aeruginosa arylsulfatase (PaS) for increased activity in the hydrolysis of testosterone sulfate (pictured), and also in a separate study to introduce wholly new activity for the hydrolysis of etiocholanolone sulfate. These enzyme have become useful new tools in the study of the steroid metabolome and have even been applied in fight against doping in sport. This project will employ the tools of directed evolution to develop new enzymes for the analytical sample preparation and the synthesis of steroid glucuronide conjugates.