William Thomas Astbury
25 February 1898
|Died||4 June 1961 (aged 63)|
|Alma mater||University of Cambridge|
|Awards||Fellow of the Royal Society|
|Fields||Physics, Molecular biology|
|Institutions||University College London|
University of Leeds
|Doctoral advisor||William Henry Bragg|
Astbury made early X-ray diffraction studies of biological molecules. His work on keratin helped Linus Pauling discover the alpha helix. He also studied the structure for DNA in 1937 and made the first step in working out its structure.
The road to DNA[change | change source]
In 1937 Torbjörn Caspersson of Sweden sent him well-prepared samples of DNA from calf thymus. The fact that DNA produced a diffraction pattern showed it had a regular structure. Astbury reported that DNA's structure repeated every 2.7 nanometres and that the bases lay flat, stacked, 0.34 nanometres apart. At a symposium in 1938 at Cold Spring Harbor, Astbury pointed out that the 0.34 nanometre spacing was the same as amino acids in polypeptide chains. Actually, the spacing of the bases in the B-form of DNA is 0.332 nm.
In 1946 Astbury presented a paper at a symposium in Cambridge in which he said: "Biosynthesis is supremely a question of fitting molecules or parts of molecules against another... one of the great biological developments of our time is the realisation that probably the most fundamental interaction of all is that between the proteins and the nucleic acids". He also said that the spacing between the nucleotides and the spacing of amino acids in proteins "was not an arithmetical accident".
Astbury was unable to propose the correct structure of DNA from his data. However in 1952 Linus Pauling used Astbury's insufficient data to propose a structure for DNA, which was also incorrect. Nevertheless Astbury's work encouraged Maurice Wilkins, Raymond Gosling and Rosalind Franklin at Kings College, London. Their X-ray crystallography results were used by Francis Crick and James D. Watson to identify the structure of DNA in 1953.
References[change | change source]
- Bernal J.D. (1963). "William Thomas Astbury 1898-1961". Biographical Memoirs of Fellows of the Royal Society. 9: 1–01. doi:10.1098/rsbm.1963.0001.
- G Ferry 2014. Of DNA and broken dreams, Nature 510 (7503), 32-33.
- Olby, Robert 1974. The path to the double helix. Seattle: University of Washington Press, especially chapters 4, 5, 12 and 13. ISBN 0-295-95359-4