Evidence for the Pauling-Corey alpha-Helix in Synthetic Polypeptides [Editorial letter]


Title:
Evidence for the Pauling-Corey alpha-Helix in Synthetic Polypeptides [Editorial letter]
Creator:
Cochran, William
Crick, Francis, 1916-2004
Date:
9 February 1952
Description:
In this letter to the editors of Nature, Crick and William Cochran previewed calculations, published in greater detail shortly thereafter, that enabled them to predict the X-ray diffraction pattern produced by a crystal with a helical shape whose atoms are arranged at regular intervals along its axis. Their theory stated that for crystals with a helical shape, the X-ray pattern can be calculated by a combination of "Bessel functions," which arise in structures of cylindrical symmetry, such as a helix. Their calculations supported Linus Pauling and Robert Corey's finding that many polypeptides, molecules that consist of a sequence of amino acids, including most proteins, are in the shape of a single-stranded helix, which Pauling and Corey dubbed the alpha helix. Having provided mathematical proof that specific two-dimensional X-ray diffraction patterns reflect the three-dimensional shape of a helix later made it easier for Crick to discern that X-ray images of DNA fibers taken by Rosalind Franklin revealed the helical structure of DNA and the ladder spacing of its nitrogenous bases, because these images conformed to Crick's and Cochran's calculations.
Periodical:
Nature
Publisher:
Nature Publishing Group
Rights:
Reproduced with permission of the Nature Publishing Group. and http://www.nature.com/nature/index.html
Genre:
Articles
Letters (correspondence)
Format:
Text
Extent:
2 pages
Language:
English
Legacy Source Citation:
Periodical. Cochran, William, and Francis Crick. "Evidence for the Pauling-Corey alpha-Helix in Synthetic Polypeptides" [Editorial letter]. Nature 169, 4293 (9 February 1952): 234-235. Article. Letter (correspondence). 2 Images.. Nature
Legacy ID:
SCBCDM
NLM ID:
101584582X455
Profiles Collection:
The Francis Crick Papers
Story Section:
Biographical Information