Maurice Wilkins

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Maurice Wilkins
Discovery of the DNA Double Helix
Francis Crick
Rosalind Franklin
James Watson
Maurice Wilkins
Maurice Hugh Frederick Wilkins

Maurice Hugh Frederick Wilkins (December 15, 1916 – October 5, 2004) was a New Zealand-born physicist and Nobel Laureate who contributed research in the fields of phosphorescence, radar, isotope separation, and X-ray diffraction. He was most widely known for his work at King's College London on the structure of DNA, a molecule which stores genetic information, for which he, Francis Crick and James Watson were awarded the 1962 Nobel Prize for Physiology or Medicine for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material[1]. A memorable quote:

"How is Cambridge? Is the cold wind blowing across the fens, frisking up the waters of the Cam, whistling through the barbed wire on college walls, rattling the chain padlocks on college gates and causing a healthy glow to appear in the faces of bedmakers and undergraduates scurrying across the cobbles to the college bathroom? Is it blowing in under the door of the Strangeways, congealing the culture media and causing all honest amphibians to hibernate?" (MHF Wilkins,1948? to FHC Crick; quoted by Robert Olby, 1974; pp 353)


Contents

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Early Life and Career

Wilkins was born in Pongaroa, north Wairarapa, New Zealand where his father was a medical doctor. His family moved to Birmingham, England when he was 6, where he subsequently attended King Edward's School at the age of 11. He later studied physics at St. John's College, Cambridge, then in 1940 he received his Ph.D. in physics at the University of Birmingham with a dissertation on phosphors. During World War II he developed improved radar screens at Birmingham, then worked on isotope separation at the Manhattan Project at the University of California, Berkeley for two years before returning to King's College London. "After the war I wondered what I would do, as I was very disgusted with the dropping of two bombs on civilian centres in Japan," he told Britain's Encounter radio programme in 1999.

In 1946 the physicist John Randall was placed in charge of a new biophysics laboratory at King's College. The plan was to hire physicists such as Wilkins to work on problems in biology. When Francis Crick first met Wilkins he was not convinced that the King's College laboratory had anything like a clear plan of attack. There seemed to be a vague hope that by applying techniques like Ultraviolet light microscopy (Wilkins) and electron microscopy (Randall), new insights could be gained into cell structure and function. By 1950, Randall was gearing up the laboratory for work on proteins. His original plan for Rosalind Franklin was that she do X-ray diffraction studies on proteins. Wilkins' work on DNA changed that. By 1951, Randall had established a major effort to solve the structure of collagen and Wilkins and Franklin represented a parallel effort to determine the structure of DNA. In the meantime, Maurice Wilkins' friend Francis Crick had joined forces with James Watson at the Cavendish Laboratory, Cambridge under Lawrence Bragg.

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DNA

DNA pioneers
William Astbury
Oswald Avery
Erwin Chargaff
Max Delbrück
Jerry Donohue
Raymond Gosling
Phoebus Levene
Linus Pauling
Sir John Randall
Erwin Schrödinger
Alec Stokes
Herbert Wilson

At King's College Wilkins pursued, among other things X-ray diffraction work on DNA that had been obtained from calf thymus by the Swiss scientist Rudolf Signer. The DNA from Signer's lab was much more intact than the DNA which had previously been isolated. Wilkins discovered that it was possible to produce thin threads from this concentrated DNA solution that contained highly ordered arrays of DNA suitable for the production of X-ray diffraction patterns[2]. Using a carefully bundled group of these DNA threads and keeping them hydrated, Wilkins and a graduate student Raymond Gosling obtained X-ray photographs of DNA that showed that the long, thin DNA molecule in the sample from Signer had a regular, crystal-like structure in these threads. This initial X-ray diffraction work at Kings College was done in May or June of 1950. It was one of the X-ray diffraction photographs taken in 1950, shown at a meeting in Naples a year later, that sparked James Watson’s interest in DNA.

At that time Wilkins also introduced Francis Crick to the importance of DNA. Wilkins knew that proper experiments on the threads of purified DNA would require better X-ray equipment. Wilkins ordered a new X-ray tube and a new microcamera. Before the DNA sample from Signer was available, Gosling had been trying to make X-ray diffraction images of sperm. Wilkins's realized that the skills of a trained X-ray crystallographer would be needed and his suggestion led to the recruitment of Rosalind Franklin to King's College by Professor Randall. However, Franklin did not start using the new equipment until September 1951. By the summer of 1950 Randall had arranged for a three year research fellowship that would fund Rosalind Franklin in his laboratory. Franklin was delayed in finishing her work in Paris. Late in 1950, Randall wrote to Franklin to inform her that rather than work on protein, she should take advantage of Wilkin's preliminary work and that she should do X-ray studies of DNA fibers made from Signer's DNA. Early in 1951 Franklin finally arrived. Wilkins was away on holiday and missed an initial meeting at which Raymond Gosling stood in for him along with Alexander R. Stokes, who, like Crick, would solve the basic mathematics that make possible a general theory of how helical structures diffract X-rays. No work had been done on DNA in the laboratory for several months; the new X-ray tube sat unused, waiting for Franklin. Franklin ended up with the DNA from Signer, Gosling became her PhD student and she had the expectation that DNA X-ray diffraction work was her project. Wilkins returned to the laboratory expecting that Franklin would be his collaborator and that they would work together on the DNA project that he had started. It was inevitable that when Franklin and Wilkins met, they would clash. Franklin felt that DNA was now her project and would not collaborate with Wilkins, who then pursued parallel studies.

By November 1951 Wilkins thought he had evidence that DNA in cells as well as purified DNA had a helical structure[3]. Alexander Stokes had solved the basic mathematics of helical diffraction theory and thought that Wilkin's X-ray diffraction data indicated a helical structure in DNA. Wilkins met with Watson and Crick and told them about his results. This information from Wilkins along with additional information gained by Watson when he heard Franklin talk about her research during a King's College research meeting, stimulated Watson and Crick to create their first molecular model of DNA, a model with the phosphate backbones at the center. Upon viewing the model of the proposed structure, Franklin told Watson and Crick that it was wrong. Franklin knew that because of basic chemical principles the hydrophilic backbones should go on the outside of the molecule where they could interact with water. Crick tried to get Wilkins to continue with additional molecular modeling efforts, but Wilkins did not take this approach. During 1952, Franklin also refused to participate in molecular modeling efforts and continued to work on step-by-step detailed analysis of her X-ray diffraction data (Patterson synthesis). Neither Wilkins or Franklin was happy. By Spring of 1952, Franklin had received permission from Randall to request permission to transfer her fellowship so that she could leave King's College and work in John Bernal's laboratory. However, Franklin remained at King's College for another year.

By early 1953, it was clear that Franklin would simply drop her DNA work at the end of her fellowship that summer, or even sooner. Linus Pauling had published a proposed but incorrect structure of DNA, making the same basic error that had been made by Watson and Crick a year earlier. Among those working on DNA in England, some feared that Pauling would quickly solve the DNA structure once he recognized his error and put the backbones of the nucleotide chains on the outside of a model of DNA. Wilkins' frustrations with Franklin eventually led him to show Watson one of Franklin's high quality (taken in 1952 with the new X-ray tube Wilkins had ordered) X-ray images, without permission from Franklin. It is unclear how Wilkins came to have the photo. After March 1952 Franklin concentrated on the X-ray data for the A-form of less hydrated DNA while Wilkins tried to work on the B-form. Wilkins was handicapped because Franklin had all of the good DNA. Wilkins got new DNA, but it was not as good as the original sample he had used in 1950 and which Franklin continued to use. About his only new results were for biological samples like sperm cells, which seemed to also suggest a helical structure for DNA. In the middle of 1952 Wilkins had for a time abandoned further DNA work when Franklin reported to him that she thought the A-form was not helical. If so, Wilkins feared, the data suggesting a helical structure might just be an artifact.

In early 1953 Watson visited King's College and Wilkins showed him a high quality image of the B-form X-ray diffraction pattern that had been produced by Franklin in March 1952. With the knowledge that Pauling was working on DNA and had submitted a model of DNA for publication, Watson and Francis Crick mounted one more concentrated effort to deduce the structure of DNA. Watson and Crick asked their superiors for access to a progress reports from King's College that included useful information from Franklin about the features of DNA she had deduced from her X-ray diffraction data. Fearful that Pauling would solve the structure first, Crick was granted access to Franklin's data by his boss, Max Perutz. Watson and Crick published their proposed DNA double helical structure in a ground-breaking paper in the journal Nature in April of 1953. In this paper Watson and Crick acknowledged that they had been "stimulated by.... the unpublished results and ideas" of Wilkins and Franklin.

In recognition of the contribution from King's College, Watson and Crick agreed that Wilkins, Stokes and Wilson[4] and Franklin with Gosling should each publish the supporting evidence from x-ray diffraction for the proposed structure in separate articles in the same issue of Nature. Unfortunately in his autobiography "The Third Man of The Double Helix", Maurice Wilkins does not specifically credit Stokes and Wilson as co-authors of their paper in "Nature"; whether this was deliberate on his part or just down to rather poor sub-editing by OUP is not known.

Wilkins and others went on to repeat and extend much of Franklin's work to prove that the double-helical structure was indeed correct, a process that took many years. Some in the molecular biology community believe that since Franklin died early, and Wilkins was much less of a publicity-seeker, that Watson and Crick have in the popular mind overshadowed Wilkins and Franklin to an undeserved degree.

He married his second wife Patricia Ann Chidgey in 1959. They had four children, Sarah, George, Emily and William; his previous marriage to an art student called Ruth in California resulting in a son, was dissolved and Wilkins returned to England alone in July 1945.

In 1960 he was presented with the American Public Health Association's Albert Lasker Award, and in 1962 he was made a Companion of the British Empire. Also in 1962 he shared the Nobel Prize in Physiology or Medicine with Watson and Crick. Some in the molecular biology community believe that since Franklin died early, and Wilkins was much less of a publicity-seeker, that Watson and Crick have in the popular mind overshadowed Wilkins and Franklin to an undeserved degree.

He published his autobiography, "The Third Man of the Double Helix," in 2003. He died a year later, only a few months after the death of Francis Crick. At the time of his death, he was still a member of King's College London staff and remained an ardent campaigner against nuclear weapons.

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References

  1. ^  The Nobel Prize in Physiology or Medicine 1962. Nobel Prize Site for Nobel Prize in Physiology or Medicine 1962.
  2. ^  See Figure 1 of the Nobel lecture by Wilkins. See other examples at the King's College website for DNA structure.
  3. ^  See Chapter 2 of The Eighth Day of Creation: Makers of the Revolution in Biology by Horace Freeland Judson published by Cold Spring Harbor Laboratory Press (1996) ISBN 0879694785.
  4. ^  "Molecular Structure of Deoxypentose Nucleic Acids" by M. H. F. Wilkins, A.R. Stokes A.R. and H. R. Wilson in Nature (1953) volume 171 pages 738-740. Download the full text in PDF format.
  5. Watson, James D. "The Double Helix: A Personal Account of the Discovery of the Structure of DNA"; The Norton Critical Edition, which was published in 1980, edited by Gunther S. Stent.


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Books featuring Maurice Hugh Frederick Wilkins

  • Chomet, S. (Ed.), D.N.A. Genesis of a Discovery, 1994, Newman- Hemisphere Press, London; NB a few copies are available from Newman-Hemisphere at 101 Swan Court, London SW3 5RY(phone: 07092 060530).
  • Maddox, Brenda Rosalind Franklin: The Dark Lady of DNA, 2002. ISBN 0060184078.
  • Sayre, Anne 1975. Rosalind Franklin and DNA. New York: W.W. Norton and Company. ISBN 0393320448.
  • Wilkins, Maurice, The Third Man of the Double Helix: The Autobiography of Maurice Wilkins ISBN 0198606656.
  • Crick, FrancisWhat Mad Pursuit: A Personal View of Scientific Discovery (Basic Books reprint edition, 1990) ISBN 0465091385
  • Watson, James D., The Double Helix: A Personal Account of the Discovery of the Structure of DNA, Atheneum, 1980, ISBN 0689706022 (first published in 1968)
  • Krude, Torsten (Ed.) DNA Changing Science and Society: The Darwin Lectures for 2003 CUP 2003, includes a lecture by Sir Aaron Klug on Rosalind Franklin's involvement in the determination of the structure of DNA.

    DNA structure research at King's College London 1947-1959
    Maurice Wilkins | Rosalind Franklin | Raymond Gosling | Alec Stokes | Herbert Wilson | John Randall|		 Image:DNA icon (25x25).png
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External links