Research in the Müller lab focuses on developing and applying chemical biology tools elucidate how proteins are controlled by molecular on/off switches, so-called post-translational modifications. We are particularly interested in modifications of the polypeptide backbone, and how these and more traditional modifications are involved in cellular life and death decisions. To answer these questions, we use semi-synthesis to generate ‘designer’ proteins – including the tumour suppressor p53, viral anticancer proteins and histones – allowing us to directly measure the structural and functional consequences of modifications. In parallel, we develop novel strategies to discover backbone modifications and their roles in molecular ageing and signalling. Manuel is a Wellcome Trust/Royal Society Sir Henry Dale Fellow.