Ephraim Katzir, the eminent biophysicist, was best known for his pioneering studies of proteins that contributed to the human genome project, the international research effort to understand the genetic make-up of human beings by deciphering the genetic code. Between May 1973 and May 1978, he served as the fourth President of Israel.

His research contributed to the production of synthetic antigens, molecules (usually proteins) on the surface of cells, viruses or bacteria, which prompt the generation of antibodies and which can trigger an immune response.

His work also contributed to the understanding of the various steps of immune response. The immune system is how the body recognises and destroys bacteria, viruses and substances that appear foreign and harmful. It does so by responding to antigens.

Katzir’s work on the properties of polyamino acid, a synthetic polymer made up of many repeating units of amino acids, led to the development of the drug Copaxone (glatiramer acetate). Copaxone, developed at the Weizmann Institute, is used worldwide to treat multiple sclerosis.

He also developed a method for binding enzymes (organic molecules that speed up chemical processes) to surfaces and molecules that led to the development of enzyme engineering, an activity that plays a key role in the food and pharmaceutical industries.

Ephraim Katchalski Katzir was born in 1916 in Kiev, Ukraine, where his parents had fled during the First World War. He spent his early childhood in Kiev and in Lodz, Poland. In 1925, when he was 9, the family emigrated to British-controlled Palestine and settled in Jerusalem.

His brother Aharon, a noted professor of chemical physics, was murdered on May 30, 1972 in the Lod airport terrorist attack in Tel Aviv by members of the Japanese Red Army.

Katzir was educated at the Hebrew Gymnasium in Rehavia. In 1932 he enrolled in the biology department at the Hebrew University, Mount Scopus. He first studied bacteriology, botany and zoology and then concentrated on biochemistry and organic chemistry. In 1938 he received his MSc and, in 1941 his PhD for a thesis on synthetic polymers (large molecules composed of repeating structural units) of amino acids.

While a student in Palestine he was a member of Haganah, a Jewish paramilitary underground organisation that later became the core of the Israeli Defence Forces. Later he was involved in Hemed (an acronym for Cheyl Mada or science unit), the Israel Army’s science corps, founded in 1948; he became its commander. In 1966 he became the Chief Scientist of the Israeli Defence Forces.

After obtaining his doctorate, Katzir went to America to continue his studies at the Polytechnic Institute of Brooklyn, New York; Columbia University, New York; and Harvard University, Cambridge, Massachusetts.

In 1946 Chaim Weitzmann recruited him to help to set up the Weizmann Institute in Rehovot. He remained associated with the institute throughout his career, becoming the Theodore R. Racoosin Professor of Biophysics in the Department of Membrane Research and Biophysics.

After stepping down from the Israeli presidency (an apolitical post designed to be above controversy) in 1978, he returned to the institute and was appointed institute professor, a prestigious award given to outstanding scientists. Devoting himself to the promotion of biotechnological research in Israel, he founded the Department of Biotechnology at Tel Aviv University, continuing his efforts to establish science-based industries in Israel.

Towards the end of his scientific career he worked with a team at the Weizmann Institute that discovered an important aspect of the effects of snake venom on the body. He also worked on the computer modelling of proteins.

Apart from his scientific research, Katzir involved himself in the social and educational aspects of science and in the development of national science policy. He wrote hundreds of scientific papers. He was elected a foreign member of the Royal Society of London in 1977 and a member of the US National Academy of Sciences. He was appointed to France’s Legion of Honour.

In 1959 he received the Israel Prize for natural sciences. In 1985 he was the first recipient of the Japan Prize, awarded for work on immobilised enzymes used in oral antibiotics. He was given honorary doctorates by more than a dozen universities.

A man with outstanding abilities, Katzir was known for his kindness, modesty and simplicity. His wife, Nina, and two daughters predeceased him. He is survived by his son.

Professor Ephraim Katzir, biophysicist and former President of Israel, was born on May 16, 1916. He died on May 30, 2009, aged 93