Correspondence

LP to Jerry Donohue. December 23, 1952.

LP's reply - Page 01

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Title:	Linus Pauling's correspondence to Jerry Donohue [1 of 3]
Alternative Title:	Linus Pauling's correspondence to Jerry Donohue, December 23, 1952
Creator:	Pauling, Linus, 1901-
Publisher:
Date:	1952-12-23
Subject:	Chemical bonds Chemical structure Pauling, Linus, 1901- -- Correspondence
Description:
Type:	Text
Format:	text/plain
Language:	en
Identifier:	donohue03-pg01.jpg
Source:	Master file format: TIFF, 600 dpi, Epson GT-10000+ flatbed scanner.
Rights:	http://osulibrary.oregonstate.edu/specialcollections/coll/pauling/dna/copyright.html
Full Text:	Dear Jerry: I am interested to learn about the helix is that you have been working on. Asked to the helix 3.0(10) this is the one that is described in our paper with Branson, as corresponding to the rotational angle 120 degrees (which gives 3.0 residues per turn), and as having the same orientation as the Alpha helix. Dr. Branson concluded from his very complicated analytical treatment that the hydrogen bombs are badly bent. Also, the crude model day he made indicated similar bad been deemed, although our new models showed that this training in the hydrogen bond is small--there is a been deemed by about 40 degrees at the oxygen atom, which, however, is of course allowed. Our van der Waals model indicates that the helix is too tight, introducing steric hindrance along the axis, but of course van der Waals radii are not very reliable. Also, I am reasonably assured that this is the structure that Higgins discussed, as having three residues per turn; it is, I think, the one day he got common at the time of the New York meeting in the fall of 1951 common to beat the Alpha helix. He did not discuss the Alpha helix. I am sure that the helix 4.4(16) is the one that Barbara Low has described. We had made an investigation of it, and some months ago I asked Dr. Yankel to calculate its radial distribution function, using the helicometer. I do not think he has yet made this calculation--he decided to rebuild the helicometer, and has put into operation only recently. In our considerations about 4.4(16), carried out before we knew it was Barbara Low's structure, we decided that the strain should be relieved mainly by twisting the amide group from the planar configuration, rather than increasing the Alpha carbon angle. Probably the strain is relieved partially in each of these places. We have not made in a study of 4.4(14), which is like the gamma helix, but twisted more tightly. (This series up Alpha helix is has subscript 3n + 4(p) and the series of gamma helix is has subscript 3n+5.) the amount of strain is so great--use a 7 degrees on the Alpha carbon angle and six degrees twist of the amide group--that this configuration shed, we think, be ruled out. I think, although I am not sure, that it is mentioned under the angle 108 degrees in our cable--this corresponds to 3.3(14), but we were putting all of the strain into the hydrogen bombs. Perhaps 108 degrees represents 3.3(11), with 3.3(14) left out because of its deviation from our assumed structural features.