"The height of the vector rods in the three-dimensional Patterson of haemoglobin"

Date:
1952
Reference:
PP/CRI/I/1/2
Catalogue details

Licence: In copyright

Credit: "The height of the vector rods in the three-dimensional Patterson of haemoglobin". Source: Wellcome Collection.

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    Reprinted from Acta Crystalloqraphica, Vol. 5, Part 3, May 1952 Acta Cryst. (1952). 5, 381 The Height of the Vector Rods in the Three-Dimensional Patterson of Haemoglobin By F. H. C. Crick The Medical Research Council Unit for the Study of the Molecular Structure of Biological Systems, Cavendish Laboratory, Cambridge, England (.Received 15 November 1951) A method is described for calculating the average height of the vector rods in the three-dimensional Patterson of haemoglobin. The calculations have been carried out for the a-helix. They show that the simple models previously considered for haemoglobin give peaks which are too high, and that to obtain even rough agreement either less than about half the protein must be put into chains parallel to the X axis or considerable irregularity must be introduced. The evidence suggests that the folded polypeptide chain does not run in one direction for more than 20 Á at a stretch. Introduction which Perutz (1949) interpreted in terms of straight The three-dimensional Patterson synthesis of horse rods of high electron density in the molecule; he methaemoglobin has, as one of its features, rod-shaped suggested that these rods were due to folded poly- regions of high vector density, parallel to the X axis, peptide chains arranged in hexagonal close packing