Definição e significado de Maurice_Wilkins

Maurice Wilkins
Maurice Wilkins
Born	(1916-12-15)15 December 1916 Pongaroa, Wairarapa, New Zealand
Died	5 October 2004(2004-10-05) (aged 87) Blackheath, London, United Kingdom
Fields	Physics, Molecular biology
Institutions	University of California, Berkeley
Known for	X-ray diffraction, DNA
Notable awards	Nobel Prize in Physiology or Medicine (1962)

Maurice Hugh Frederick Wilkins CBE FRS (15 December 1916 – 5 October 2004)^[1] was a New Zealand-born English physicist and molecular biologist, and Nobel Laureate whose research contributed to the scientific understanding of phosphorescence, isotope separation, optical microscopy and X-ray diffraction, and to the development of radar. He is best known for his work at King's College London on the structure of DNA. In recognition of this work, 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."^[2]

  Birth and early education

  Monument to Maurice Wilkins, Main Street, Pongaroa, New Zealand

Wilkins was born in Pongaroa, north Wairarapa, New Zealand where his father, Edgar Henry Wilkins was a medical doctor. His family had come from Dublin, where his paternal and maternal grandfathers were, respectively, Headmaster of Dublin High School and a Chief of Police. The Wilkins moved to Birmingham, England when Maurice was 6. Later, he attended Wylde Green College and then went to King Edward's School from 1929 to 1935.

  Academic career, 1936–1950

Wilkins went up to St John's College, Cambridge in 1935. He studied physics, within the Natural Sciences Tripos, and received a B.A. Mark Oliphant who was one of Wilkin's tutors at St. John's had been appointed to the Chair of Physics at the University of Birmingham, and had appointed John Randall to his staff. Wilkins became a Ph.D. student of Randall. In 1945, they published three papers in the Proceedings of the Royal Society on phosphorescence and electron traps. Wilkins received his Ph.D. for this work.^{[citation needed]}

During World War II Wilkins developed improved radar screens at Birmingham, then worked on isotope separation at the Manhattan Project at the University of California, Berkeley during the years 1944–45.^[3]

Meanwhile, Randall had been appointed to the Chair of Physics at St. Andrews University. In 1945, he appointed Wilkins as Assistant Lecturer in his department. Randall was negotiating with the Medical Research Council (MRC) to set up a laboratory to apply the experimental methods of physics to problems of biology. The combination of these disciplines as biophysics was a novel idea. The MRC told Randall that this had to be done in another university. In 1946 Randall was appointed Wheatstone Professor of Physics, in charge of the entire Physics department at King's College, London, with the funding to set up a Biophysics Unit. He brought Wilkins with him, as Assistant Director of the unit. They appointed a team of scientists trained in both the physical and biological sciences. The "management philosophy" was to explore the use of many techniques in parallel, to find which looked promising, and then to focus on these. Wilkins, as the scientist with most diverse experience of physics and Assistant Director of the unit, had general oversight of the varied projects besides direct involvement in his personal research projects that included optical microscopy.^{[citation needed]}

King's College received funding to build completely new Physics and Engineering Departments where vaults beneath the Strand level College forecourt had been destroyed by bombs during the War. The Biophysics Unit, several more experimental physics groups and the theoretical group started to move in, during the early months of 1952. The laboratories were opened formally by Lord Cherwell on 27 June. Wilkins' article for Nature described both departments, consistent with his leadership role and prestige within the College at large.^[4]

  DNA

By 1950, preliminary studies of proteins were progressing in the MRC unit. Randall's 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 under the supervision of Max Perutz at the Cavendish Laboratory, Cambridge and under the overall direction of Lawrence Bragg.^{[citation needed]}

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.^[5] 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 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.^{[citation needed]}

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. 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 Wilkins's preliminary work^{[citation needed]} and that she should do x-ray studies of DNA fibers made from Signer's samples of 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 Alex 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. Franklin felt that DNA was now her project and would not collaborate with Wilkins, who then pursued parallel studies.^{[citation needed]}

By November 1951 Wilkins had evidence that DNA in cells as well as purified DNA had a helical structure.^[6] Alex Stokes had solved the basic mathematics of helical diffraction theory and thought that Wilkins'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 from 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). By the spring of 1952, Franklin had received permission from Randall to ask to transfer her fellowship so that she could leave King's College and work in John Bernal's laboratory at Birkbeck College, also in London. However, Franklin remained at King's College for another year.^{[citation needed]}

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 due to illness. Linus Pauling had published a proposed but incorrect structure of DNA, making the same basic error that Watson and Crick had made a year earlier. Some of those working on DNA in the United Kingdom 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. 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 hydrated B-form. Wilkins was handicapped because Franklin had all of the good DNA. Wilkins got new DNA samples, but it was not as good as the original sample he had used in 1950 and which Franklin continued to use. Most of his 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 her results made her doubt the helical nature of the A-form. Wilkins feared that the data suggesting a helical structure might just be an artifact.^{[citation needed]}

In early 1953 Watson visited King's College and Wilkins showed him a high quality image of the B-form x-ray diffraction pattern, now identified as photograph 51, that Franklin had produced in March 1952. With the knowledge that Pauling was working on DNA and had submitted a model of DNA for publication, Watson and Crick mounted one more concentrated effort to deduce the structure of DNA. Through Max Perutz, his thesis supervisor, Crick gained access to a progress report from King's College that included useful information from Franklin about the features of DNA she had deduced from her x-ray diffraction data. Watson and Crick published their proposed DNA double helical structure in a paper in the journal Nature in April 1953. In this paper Watson and Crick acknowledged that they had been "stimulated by.... the unpublished results and ideas" of Wilkins and Franklin.^{[citation needed]}

The first Watson-Crick paper appeared in Nature on 25 April 1953. Sir Lawrence Bragg, the director of the Cavendish Laboratory, where Watson and Crick worked, gave a talk at Guys Hospital Medical School in London on Thursday 14 May 1953 which resulted in an article by Ritchie Calder in the News Chronicle of London, on Friday 15 May 1953, entitled "Why You Are You. Nearer Secret of Life." The news reached readers of The New York Times the next day; Victor K. McElheny, in researching his biography of Watson, Watson and DNA: Making a Scientific Revolution, found a clipping of a six-paragraph New York Times article written from London and dated 16 May 1953 with the headline "Form of 'Life Unit' in Cell Is Scanned." The article ran in an early edition and was then pulled to make space for news deemed more important. (The New York Times subsequently ran a longer article on 12 June 1953). The Cambridge University undergraduate newspaper Varsity also ran its own short article on the discovery on Saturday 30 May 1953. Bragg's original announcement at a Solvay conference on proteins in Belgium on 8 April 1953 went unreported by the press.^{[citation needed]}

The members of the Cambridge and King's College laboratories agreed to report their interlocking work in three papers with continuous pagination in Nature.^[7][8][9] Wilkins then led the team that performed a range of meticulous experiments to establish the helical model rigorously.

  Personal life

Wilkins married an art student, Ruth, when he was at Berkeley. They had a son. He married his second wife Patricia Ann Chidgey in 1959. They had four children, Sarah, George, Emily and William.

He published his autobiography, The Third Man of the Double Helix, in 2003.

Formerly classified UK security service papers reveal that, while working on the project, Wilkins came under suspicion of leaking atomic secrets. The files, released in August 2010, indicate surveillance of Wilkins ended by 1953.^[10] "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.^[11]

  Recognition

  A plaque commemorating Maurice Wilkins and his discovery, beneath the monument, Pongaroa, New Zealand

In 1960 he was presented with the American Public Health Association's Albert Lasker Award, and in 1962 he was made a Commander of the British Empire. Also in 1962 he shared the Nobel Prize in Physiology or Medicine with Watson and Crick for the discovery of the structure of DNA.

On Saturday 20 October 1962 the award of Nobel prizes to John Kendrew and Max Perutz, and to Crick, Watson, and Wilkins was satirised in a short sketch in the BBC TV programme That Was The Week That Was with the Nobel Prizes being referred to as 'The Alfred Nobel Peace Pools.'

In 1969, Wilkins became the founding President of the British Society for Social Responsibility in Science.

In 2000, King's College London opened the Franklin-Wilkins Building in honour of Dr. Franklin's and Professor Wilkins' work at the college.^[12]

The wording on the new DNA sculpture (which was donated by James Watson) outside Clare College's Thirkill Court, Cambridge, England is

a) on the base:

i) "These strands unravel during cell reproduction. Genes are encoded in the sequence of bases."

ii) "The double helix model was supported by the work of Rosalind Franklin and Maurice Wilkins."

b) on the helices:

i) "The structure of DNA was discovered in 1953 by Francis Crick and James Watson while Watson lived here at Clare."

ii) "The molecule of DNA has two helical strands that are linked by base pairs Adenine – Thymine or Guanine – Cytosine."

  References

  Books featuring Maurice Wilkins

• Robert Olby; 'Wilkins, Maurice Hugh Frederick (1916–2004), Oxford Dictionary of National Biography, online edn, Oxford University Press, Jan 2008
• Robert Olby; "Francis Crick: Hunter of Life's Secrets", Cold Spring Harbor Laboratory Press, ISBN 978-0-87969-798-3, published in August 2009.
• John Finch; 'A Nobel Fellow On Every Floor', Medical Research Council 2008, 381 pp, ISBN 978-1-84046-940-0; this book is all about the MRC Laboratory of Molecular Biology, Cambridge
• Robert Olby; "The Path to The Double Helix: Discovery of DNA"; first published in October 1974 by MacMillan, with foreword by Francis Crick; ISBN 0-486-68117-3; the definitive DNA textbook, revised in 1994, with a 9 page postscript.
• Horace Freeland Judson, "The Eighth Day of Creation. Makers of the Revolution in Biology"; CSHL Press 1996 ISBN 0-87969-478-5.
• 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:ISBN 0-393-01245-X.
• 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 0-06-018407-8.
• Sayre, Anne 1975. Rosalind Franklin and DNA. New York: W.W. Norton and Company. ISBN 0-393-32044-8.
• Wilkins, Maurice, The Third Man of the Double Helix: The Autobiography of Maurice Wilkins ISBN 0-19-860665-6.
• Crick, Francis, 1990. What Mad Pursuit: A Personal View of Scientific Discovery (Basic Books reprint edition) ISBN 0-465-09138-5
• Watson, James D., The Double Helix: A Personal Account of the Discovery of the Structure of DNA, Atheneum, 1980, ISBN 0-689-70602-2 (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.
• Ridley, Matt; "Francis Crick: Discoverer of the Genetic Code (Eminent Lives)" was first published in June 2006 in the US and then in the UK September 2006, by HarperCollins Publishers; 192 pp, ISBN 0-06-082333-X; this short book is in the publisher's "Eminent Lives" series.
• "Light Is A Messenger, the life and science of William Lawrence Bragg" by Graeme Hunter, ISBN 0-19-852921-X; Oxford University Press, 2004.
• "Designs For Life: Molecular Biology After World War II" by Soraya De Chadarevian; CUP 2002, 444 pp; ISBN 0-521-57078-6; it includes James Watson's "well kept open secret" from April 2003!
• Tait, Sylvia & James "A Quartet of Unlikely Discoveries" (Athena Press 2004) ISBN 1-84401-343-X

  External links

• Professor Maurice Wilkins, Obituary from The Independent on Sunday, 9 October 2004.
• Olby, R. (2003). "Quiet debut for the double helix". Nature 421 (6921): 402–405. DOI:10.1038/nature01397. PMID 12540907. http://josephgroup.ucsd.edu/CHEM13/DNA1.pdf.  edit
• for the People's Archive/BBC 90 story interview with Crick AND the 236 story interview with Brenner.
• Presentation speech at the Nobel Prize ceremony in 1962.
• Reading University site on 50th anniversary of Discovery of the structure of DNA. Includes a list of Books on the subject.
• Biography (from Nobel)
• Biography (from the New Zealand Edge)
• Discovery Story in BA Magazine
• DNA: The King's Story detailing Wilkins' involvement in elucidating the structure of DNA
• DNA and Social Responsibility Project: Archiving Maurice Wilkin's Personal Papers
• List of classic papers in Nature on DNA structure
• Listen to Francis Crick and James Watson talking on the BBC
• [1] – for reproduction of the original text in June 1953.
• [2] for Lynne Elkins' article on Franklin.
• New York Times 50th anniversary series of excellent articles.
• [3] The first American newspaper coverage of the discovery of the DNA structure: Saturday, 13 June 1953 The New York Times
• Listen to an oral history interview with Maurice Wilkins – a life story interview recorded for National Life Stories at the British Library

DNA structure research at King's College London 1947-1959 Rosalind Franklin Raymond Gosling John Randall Alexander Stokes Maurice Wilkins Herbert Wilson