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The structure of feather rachis keratin
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| Title | The structure of feather rachis keratin |
| Creator | Pauling, Linus, 1901-
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| Contributor | Corey, Robert
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| Publisher | National Academy of Sciences, Vol. 37, No.5, pp. 256-261. |
| Date | 1951-05-00 |
| Description/Note | Reprinted from the Proceedings of the National Academy of Sciences, Vol. 37, No. 5, pp. 256-261. |
| Full Text | Reprinted from the Proceedings of the NATIONAL ACADEMY of SCIENCES Vol. 37, No. 5, pp. 256-261.¦ay, 1951 THE STRUCTURE OF FEATHER RACHIS KERATIN By LINUS PAULING AND ROBERT B. COREY GATES AND CRELLIN LABORATORIES OF CHEMISTRY,* CALIFORNIA INSTITUTE OF TECHNOLOGY, PASADENA, CALIFORNIA Communicated March 31, 1951 The rachis of feathers gives rise to x-ray diffraction patterns of great complexity--they have been described as the most complex known for the naturally occurring fibrous substances. For their interpretation there is required a unit of structure with dimensions at least 9.5 A X 34 A X 94.6 A. In the following paragraphs we propose a structure for this protein that accounts for the principal features of the x-ray pattern and for some physical properties of the substance. Astbury and other workers in the field have mentioned that the pattern somewhat resembles that of stretched hair, stretched muscle, and other proteins with the β-keratin structure, but that the x-ray diagram indicates that the length per residue is only 3.07 A, somewhat shorter than expected for an extended polypeptide chain, about 3.6 A, and than observed for silk fibroin, about 3.5 A, and for the β-keratin proteins, about 3.3 A. Astbury suggested that the chains might be in a somewhat collapsed β-keratin configuration, and pointed out that the reversible extensibility of feather keratin through about 7 per cent supported this assumption.°e were struck by the identity of the indicated fiber-axis residue length, 3.07 A, and the corresponding length predicted for the undistorted pleated-sheet configuration of hydrogen-bonded polypeptide chains, described in the preceding paper, and we investigated the possibility that feather keratin is composed of these pleated sheets in parallel orientation. This can be ruled out as unsatisfactory, however, in that, although the predicted distance between chains in the direction of the hydrogen bonds, 4.75 A, agrees closely with that indicated by the x-ray diagram, about 4.68 A, the other equatorial |
| Subject | X-rays -- Diffraction
DNA -- Structure
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| Item Number | The Pauling Catalogue:
Publications Box 1951p
Folder 9 |
| Object Type | Text; |
| Material Format | text/plain; |
| Transmission Data | Master scanned with Epson GT-10000+ flatbed scanner at 600 dpi. |
| Collection Series | Published Papers
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| Copyright | http://osulibrary.orst.edu/specialcollections/coll/pauling/dna/copyright.html |
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