John Fenn: Nobel Prize-winner whose work speeded up research into new drugs

John Fenn was a Nobel Prize-winner in chemistry whose work in the field of Biomolecular Technologies helped increase the speed and development of new drugs. Fenn was in his 70s when his research made possible the rapid analysis of the structure of proteins and other biomolecules through mass spectrometry. The Swedish Royal Academy of Sciences said in its citation for the 2002 Nobel Prize, "The possibility of analysing proteins in detail has led to increased understanding of the processes of life."

Thomas Huff, vice provost of Virginia Commonwealth University, said, "John Fenn was one of those scientists whose discovery opened up an entirely new field to investigation; in his case, proteomics [the study of proteins] – the hallmark science of the post-genomic era." Fenn's work made it possible to identify proteins in seconds or minutes as opposed to days or weeks, greatly speeding up research. His work also focused on a new way of identifying and mapping carbohydrates, DNA and other large biomolecules. He shared the Nobel Prize with Koichi Tanaka, an engineer in Kyoto, Japan, and Kurt Wüthrich, a Professor of Biophysics in Zurich, who worked independently on related protein research.

Fenn had improved the technique of mass spectrometry, which identifies molecules like proteins by how quickly they are accelerated in an electric field, using electrical and magnetic fields to bend a beam of charged particles. The amount of bending, which can be measured, depends on the particles' mass and charge; knowing the charge reveals the mass, from which other important data can be inferred. However, getting large and complex molecules to remain intact while adding a charge had proven difficult as the proteins clumped together.

Fenn was able to overcome such obstacles through a process known as electrospray ionisation in which a strong electric field disperses charged droplets. As a droplet evaporates, it explodes into smaller droplets, which explode into yet smaller ones until they each contain a singled charged protein hovering in the vapour.

Biologists can now identify molecules in a matter of seconds,and the techniques have helped create a new field of biology, proteomics, in which scientists are trying to catalogue the interplay of hundreds of thousands of proteins in human cells. Speaking in 2002, Fenn said, "It's probably safe to say that every new drug that comes to the market today has a fair amount of electrospray mass spectrometry in its background and development."

After winning his Nobel, Fenn admitted, "There's an awful lot of luck in this... In fact, there's a lot of luck in science." Fenn, then on the faculty at Yale, clashed over the patent rights to electrospray ionisation as he was unhappy at the 70/30 split of profits required from patents in favour of the university. Fenn patented it himself and licensed the patent to a company he had co-founded. In 2005, a federal judge ruled that Fenn was guilty of "civil theft", assigned the patent to Yale and ordered Fenn to pay more than $1m in costs and royalties. He appealed but lost.

Born in 1917 in New York City, John Bennett Fenn was the older of two brothers. His father, Herbert, was a manager in a clothing factory and later a draughtsman at the Fokker Aircraft Factory, while his mother ran the home. In 1928 Fenn's father secured a job as a teacher of car mechanics and practical electricity at the Berea Academy in Berea, Kentucky. The young Fenn and his brother attended the academy, Fenn obtained his degree in chemistry from Berea College in 1937 before proceeding to Yale to complete his doctorate in 1940. While at Yale he married Margaret Wilson, 10 years his senior, with whom he had been smitten from the first day they met at Berea. She died in a car crash on holiday in New Zealand in 1992.

Fenn found academic life somewhat boring and described his experiments at Yale as "a boring chore with few redeeming features." He did, however, find other rewards at graduate school, including friendships, "many interactions with interesting people" and learning "to play bridge, to drink beer and to smoke a pipe." None the less, he was determined to go into industry. During the war he worked for the Monsanto Chemical Company in Anniston, Alabama, then Sharples Chemicals in Michigan, and after the war spent seven years with a small company in Richmond, Experiment Inc, which he founded with a friend; there they worked on ramjet propulsion systems for the US Navy.

In 1952, Princeton University offered Fenn the position of Director of Project SQUID, a US Navy-financed research programme in jet propulsion administered by Princeton. He accepted and also became a Professor of Aerospace and Mechanical Sciences there. Many details of that project remain classified. He moved to Yale in 1967, retiring in 1987 as an emeritus professor. He then moved to Virginia Commonwealth University in 1994, where he was to undertake his most important work. He received a number of awards and was a member of the National Academy of Sciences.

Fenn had strong views on science teaching, in particular chemistry, and expounded on them in in 2009. "Courses ought to be fun," he said. "I don't care whether we cover everything in the periodic table or not ... There's no fun any more! ... I wish we could somehow get it across that the purpose of education is to develop young peoples' minds, not fill them up with a lot of facts... Teach them how to think."

Martin Childs

John Bennett Fenn, scientist: born New York City 15 June 1917; married firstly Margaret Wilson (died 1992; three children), secondly Frederica Mullen (two stepdaughters); died Richmond, Virginia 10 December 2010.