THE pioneering Oxford scientist Dame Louise Johnson, who shed new light on the role of enzymes in health and disease, has died aged 71.

Dame Louise was David Phillips Professor of Molecular Biophysics at Oxford University from 1990 to 2007 and played an important role in the design of new drugs to tackle cancer and other fatal diseases.

As well as being a prominent figure at Oxford University, in 2003 she took on the role of director of Life Sciences at the Diamond Light Source, at Harwell, near Didcot. The particle accelerator is the largest UK-funded scientific facility to be built in more than 40 years.

Although she formally retired from her duties at the university five years ago, she continued to be involved at Diamond until early last year.

Dame Louise was born in Worcester and educated in Wimbledon and at University College, London, before moving to the Royal Institution where she completed her PhD in 1966.

She moved to Oxford in 1967 to work as a university demonstrator and lecturer in biophysics at Somerville College, becoming a Fellow of Somerville in 1973. In 1968 she married Abdus Salam, the distinguished Pakistani physicist and future Nobel laureate.

For years at Oxford she was engaged in challenging work on the structure of complex enzymes and wrote a classic textbook on protein crystallo- graphy. She was to remain at the cutting edge of protein crystallography research, introducing new techniques and instrumentation to add to understanding of complex protein structures.

Driven by the technical difficulties of her work, Dame Louise quickly realised the potential of the new source of X-rays at Diamond.

Throughout her life she was keenly interested in passing on her skills to developing countries and the Middle East and was an elected associate member of the Third World Academy for Science.

A Fellow of Corpus Christi College, Oxford, she won numerous awards and prizes, including the Novartis Medal and Prize of the Biochemical Society in 2009. She was elected a Fellow of the Royal Society in 1990 and in 2011 elected a foreign associate of the US National Academy of Sciences.

A service celebrating her life was held at Cambridge Crematorium on October 6. She is survived by her two children Umar and Sayyeda.