The Passport Imbroglio

Ava Helen and Linus Pauling's passport photo. 1953.

Ava Helen and Linus Pauling's passport photo. 1953.

A quick glance at the “Today in Linus Pauling” widget found at the top of the left sidebar of the Pauling Blog gives an excellent representation of the span and influence of Linus Pauling’s career. Rarely does a day go by where he didn’t write at least one manuscript or give a speech at a university or some other institution. Most days, readers will also note that he won some sort of award – including, of course, his two Nobel Prizes in chemistry and peace. Basically, Pauling’s career fits very well with the old cliché that anything can be done if the mind is simply set on it.

However, if one looks closely enough, a few failures can still be picked out of Pauling’s illustrious career. One of these failures is undoubtedly his attempt at determining the correct primary structure of DNA. Pauling first started working with DNA in the early 1950s, right around the time when his scientific career was reaching its peak. During this time, Pauling’s pursuits had also taken a controversial political shift – work which caused him to be denied a passport for a short period of time. This passport denial, because it is believed by many to be the reason why Pauling was beaten to the structure of DNA, is the topic of today’s post.

Near the end of 1951, Pauling received an invitation to attend a meeting of the Royal Society in England; a meeting that was specially designed for him to address questions about his protein structures. The meeting was scheduled for May 1, 1952, and promised to give Pauling an opportunity to visit King’s College in London, where he knew Maurice Wilkins had some excellent X-ray patterns of DNA.

However, when Pauling sent in his passport renewal application in January 1952, he was upset but unsurprised to find it denied by Ruth B. Shipley, the head of the State Department’s passport division. Shipley didn’t give Pauling a good reason for the denial, stating only that “the Department is of the opinion that your proposed travel would not be in the best interests of the United States.” Reading between the lines, Pauling’s liberal views had clearly earned him the label of “possible Communist,” and Shipley, who was a fervent anti-Communist, had the authority to deny passports at her discretion.

Video Link: Pauling discusses his reaction to the refusal of his passport.

Fortunately for Pauling, the delay caused by the situation was not a long one. In the summer of 1952, he sent in another passport application. Again, Shipley immediately denied it, but her decision was overruled – after much deliberation – by higher-level employees of the State Department. Eventually, Pauling was notified that he would be granted a limited passport to travel for a short period of time in England and France if he agreed to sign an affidavit stating that he wasn’t a Communist. Surprised and pleased by the news, Pauling immediately agreed and received his new passport within days.

Thus equipped with the necessary papers, Pauling traveled to England, where he stayed for a month. He visited the same places and talked with the same people that he would have earlier in the year, but he did not visit King’s College to view Wilkins’ X-ray data. As it turns out, Pauling wasn’t even thinking about DNA during his time in England.

After England, Pauling traveled to France, where he learned of the results of the Hershey-Chase blender experiment:  DNA was in fact the site of the gene, not proteins, as Pauling had believed. Upon learning of the keen importance of DNA, he decided that he would solve the structure of the molecule.

However, when he returned to Caltech in September of 1952, he continued to work almost exclusively with proteins. It wasn’t until November that Pauling would finally take a serious stab at the structure of DNA. And, as has been well-documented, even with his excellent knowledge of structural chemistry, Pauling’s data – presented in the form of blurry X-ray patterns created by William T. Astbury – was insufficient. He ended up creating a model that was nearly identical to one Watson and Crick had made over a year earlier. Of course, Pauling soon learned that his structure was incorrect, and before he could make another attempt, Watson and Crick had solved DNA.

The importance of Pauling’s passport imbroglio is, as it turns out, counter to the popular mythology of the DNA story. Although the denial of Pauling’s passport caused minor delays in his travels, it surely did not keep him from determining the structure of DNA. Even if he had traveled to England as originally planned, it is unlikely that he would have visited Wilkins to view his X-ray data. Pauling, even after finding out that DNA was extremely important, made no effort to obtain better data, nor did he even work specifically with DNA for quite some time. One is forced to conclude then, that the reason that Linus Pauling was not able to solve DNA is that he never really put his mind to the matter, not because of a pesky passport denial that delayed his travels a mere ten weeks.

For more information on Linus Pauling’s DNA pursuits, please visit the website Linus Pauling and the Race for DNA: A Documentary History. For other information on Pauling, check out the Linus Pauling Online portal.

The Fraser Structure of DNA

Today, the DNA series is continued with a post discussing a mostly correct structure that almost emerged from King’s College in the early 1950s. Although Maurice Wilkins, Rosalind Franklin, and Bruce Fraser each contributed information for the structure, it was Fraser that actually put the pieces together and built a model. Therefore, today’s post will focus on Fraser, a lesser-known player in the DNA story.

Robert Donald Bruce Fraser was born on August 14, 1924 in Ickenham, England. In 1943, he received his first of many degrees – an intermediate Bachelors of Science from Birkbeck College in London. Fraser returned to academics after a stint with the Royal Air Force that lasted from 1943 to 1946. In 1948, he received a Bachelors of Science in Physics and Math from King’s College in London. After receiving this degree, Fraser remained at King’s College for quite some time. He held a Medical Research Council Studentship position for approximately three years and received his Ph.D. in Biophysics in 1951.

During his Ph.D. candidacy, Fraser utilized infrared methods to study DNA samples prepared by his wife, Mary Fraser. The duo used the data gathered from this research to establish the idea that the large base groups in DNA sit perpendicular to the molecular axis – information that was soon published (“Physical Studies of Nucleic Acid: Evidence on the Structure of Deoxyribonucleic Acid from Measurements with Polarized Infra-Red Radiation” by Mary J. Fraser & Robert D.B. Fraser in Nature 167. Link not available).

Although DNA had yet to become a particularly important molecule in terms of research, Fraser was not the only person at King’s College working with it. Maurice Wilkins and Rosalind Franklin were also studying DNA, but neither was inclined to make a model based on their data. In fact, Franklin was strongly against model-building until the structure was completely understood.

Despite this, Fraser decided to try his hand at building a model based on both his own research as well as the research of Wilkins and Franklin. Before beginning, he discussed the molecule with both his soon-to-be famous colleagues. More specifically, he asked how many chains each thought a molecule of DNA would contain. Both said three, based on two pieces of information: a) the measurements and density for water content suggested more than one chain, and b)  two chains wouldn’t seem to fill enough space. Using this information, Fraser began to work on his model.

The structure came together very quickly. It was a rather simple model that consisted of a helical shape with three chains, the phosphate groups on the outside of the molecule, and the base groups stacked in the center. As it would turn out, this model correctly predicted almost all of the key features of DNA – the only fault was the three chain property, something that was becoming a common error.

Although Fraser created an excellent model, it did not receive any credit. As a result of Wilkins’ and Franklin’s views on model building, the structure was not to be published. After completing his doctorate work in 1952, Fraser left London and took a position as the chief of the protein chemistry division for the Commonwealth Scientific and Industrial Research Organization (CSIRO) in Melbourne, Australia.

However, this move did not put Fraser completely out of the DNA picture. In 1953, James Watson and Francis Crick were preparing to publish their structure. Wilkins, upon seeing their model, decided that Fraser should have the opportunity to publish his model before Watson and Crick’s was released. Furthermore, Wilkins wanted credit for his significant work with DNA.

Accordingly, Wilkins contacted Fraser in Australia and asked him to quickly write up his structure for an article in Nature that would be accompanied by a short note from Wilkins. Fraser complied and frantically authored a brief paper titled “The Structure of Deoxyribose Nucleic Acid.” This work took Fraser the entirety of one night, and the next morning he cabled it off to London – a rather expensive process.

Unfortunately, despite Fraser’s hard work, he was once again disappointed.

Upon the arrival of the document in London, Francis Crick decided that it should not be published. Instead, he told Wilkins that Fraser would be acknowledged by him and Watson in their article (“Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid“) and that they would state that Fraser’s paper was “in the press”. In reality, the paper was not in the press and it would, in fact, never be published.

For more information on R.D.B. Fraser’s work, visit the website Linus Pauling and the Race for DNA, available at the Linus Pauling Online portal.