“ Pauling ”

The effort to discover the structure of DNA was a race among several players. They were world-renowned chemist Linus Pauling at the California Institute of Technology, and X-ray crystallographers Maurice Wilkins and Rosalind Franklin at King’s College London, in addition to Watson and Crick at the Cavendish Laboratory, Cambridge University.

The competitive juices were flowing well before the DNA sprint was in full gear. In 1951, Pauling narrowly beat scientists at the Cavendish Lab, a top center for probing protein structure, to the discovery that certain proteins are helical. The defeat stung. When Pauling sent a paper to be published in early 1953 that proposed a three-stranded DNA structure, the head of the Cavendish gave Watson and Crick permission to work full-time on DNA’s structure. Cavendish was not about to lose twice to Pauling.

Pauling's proposed structure of DNA was a three-stranded helix with the bases facing out. While the model was wrong, Watson and Crick were sure Pauling would soon learn his error, and they estimated that he was six weeks away from the right answer. Electrified by the urgency—and by the prospect of beating a science superstar—Watson and Crick discovered the double helix after a four-week frenzy of model building.

Pauling was foiled in his attempts to see X-ray photos of DNA from King’s College—crucial evidence that inspired Watson's vision of the double helix—and had to settle for inferior older photographs. In 1952, Wilkins and the head of the King’s laboratory had denied Pauling's request to view their photos. Pauling was planning to attend a science meeting in London, where he most likely would have renewed his request in person, but the United States House Un-American Activities Committee halted Pauling’s trip, citing his antiwar activism. It was fitting, then, that Pauling, who won the Nobel Prize in Chemistry in 1954, also won the Nobel Peace Prize in 1962, the same year Watson and Crick won their Nobel Prize for discovering the double helix.

© exploratorium