William Astbury

William Thomas Astbury FRS (Bill Astbury, 25 February 1898, Longton – 4 June 1961, Leeds) was an English physicist and molecular biologist.

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 
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.Olby, Robert 1974. The path to the double helix. Seattle: University of Washington Press, especially chapters 4, 5, 12 and 13. 

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Category:British biophysicists
Category:English molecular biologists
Category:1898 births
Category:1961 deaths
Category:People from Staffordshire
Category:Fellows of the Royal Society
Category:Alumni of the University of Cambridge