William Astbury

William Thomas Astbury (February 25th 1898 - June 4th 1961) was a Physicien and molecular biologist English, pioneer in the study of the biological Molécule S by diffraction of x-rays. Its work on the Kératine provided to Linus Pauling the bases necessary to its discovery of the Hélice alpha. He also studied DNA in 1937, and reached the first stages of the comprehension of his structure.

Astbury was born in 1898 with the Stoke-one-Trent. It carries out its studies with the college of Longton, then with the Jesus College of Cambridge. During the First World War, it stops its studies to be useful in Ireland within the Royal Army Medical Body. After the war, he works with William Henry Bragg with the University College of London then at the royal Institute of London.

He works then with the Université of Leeds where he studies the properties of fibrous substances like the Kératine and the Collagène thanks to a financing of textile industry (the wool consists of keratin). In diffraction of x-rays, these substances do not lead to the observation of fine peaks as it is the case for the crystals. Astbury shows in particular that the results are different if the wool is stretched and if it is not it. Its observations seem to suggest that when keratin is not stretched, the polypeptide chains are rolled up in a helicoid way. They also show that the molecular structure has one period of 0,51 Nanomètre (the propeller makes a full rotation into 0,51 nanometer). This spacing of 0,51 nanometer for keratin presents a difficulty that Asbury does not manage to surmount in spite of its various tests of rollings up. It should be waited 13 years so that Linus Pauling and its colleagues proposes a three-dimensional molecular model of this structure: the Propeller alpha.

Astbury uses then the diffraction of x-rays to study the structure of many Protéine S (of which the Myosine or the Fibrine), and it shows that these molecules are rolled up and folded up. In 1937, Torbjörn Caspersson sends to him of Sweden of the samples of DNA of calf thymus prepared well. The fact that those allow the observation of peaks of diffraction shows that the DNA has a regular structure. It observes that the structure has one period of 2,7 nanometers and that the bases are spaced of 0,34 nanometer. With a symposium in which it has its results in 1938, it underlines the fact that this spacing of 0,34 nanometer is the same one as for the amino-acid of the polypeptide chains.

During a symposium in 1946, he declares: " Biosynthesis consists with final of the assembly of molecules or parts of molecules the ones against the others, and that one of the largest projections of biology at our time is the awakening than the most fundamental interaction is perhaps that existing between proteins and the acids nucléiques". It also declares there that spacing enters the Nucléotide S and that between the amino-acids within the proteins " is not an accident arithmétique".

However, Astbury is not able to propose a correct structure for the DNA starting from its data. In 1952, Linus Pauling also uses its data to propose a structure, which proves to be false. Nevertheless, its work is at the base of work of Maurice Wilkins and Rosalind Elsie Franklin and by of discovered there structure of the DNA by Francis Crick and James Dewey Watson in 1953.

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