15 March 1960
The Nobel Committee for Chemistry
Stockholm 50, SWEDEN
Gentlemen:
Professor Sir Lawrence Bragg has sent me a copy of his nomination of J. D. Watson, F. H. C. Crick, and M. H. F. Wilkins for
the Nobel Prize for Chemistry for 1960, for their work on the structure of deoxyribonucleic acid, and has suggested that I
express my opinion.
The hydrogen-bonded double-helix for DNA proposed by Watson and Crick has had a very great influence on the thinking of geneticists
and other biologists, and I believe that their idea is a valuable one. It is my opinion that there is little doubt that nucleic
acid molecules have a complementary structure resembling in its general nature that proposed by Watson and Crick, and that
the complementariness is determined by the formation of hydrogen bonds. The detailed nature of the structure of DNA is, I
think, still uncertain to some extent, however, whereas that of polypeptide chains in proteins is now certain.
The first detailed structure to be proposed for the nucleic acids was a triple-helix structure, with hydrogen bonds between
the phosphate groups, rather than between the nitrogen bases. This structure was proposed by Professor Robert B. Corey and
me in Proceedings of the U. S. National Academy of Sciences 39, 84-87 (1953). Watson and Crick had a manuscript of this paper
before publication, and may to some extent have been stimulated by this proposal to formulate their double-helix structure,
as well as by the x-ray photographs of Wilkins.
The detailed structure proposed by Watson and Crick has been revised somewhat by Wilkins. Moreover, Robert B. Corey and I
have pointed out that it is likely that cytosine and guanine form three hydrogen bonds, rather than two, as proposed by Watson
and Crick (L. Pauling and R. B. Corey, Archives of Biochemistry and Biophysics 65, 164-181 (1956). Also, Dr. K. Hoogsteen,
an associate of Professor Robert B. Corey, has determined the structure of a simple compound of 1-methylthymine and 9-methyladenine,
and has found that the hydrogen bonding is different from that assumed by Watson and Crick for the corresponding residues
in the nucleic acids, which suggests the possibility that a further change in the structure of nucleic acid may be found necessary.
I enclose reprints of the two papers by Professor Corey and me mentioned above and also of the paper by Dr. Hoogsteen.
It is my opinion that the present knowledge of the structure of polypeptide chains in proteins is such as to justify the award
of a Nobel Prize in this field in the near future, to Robert B. Corey for his fundamental investigations of the detailed molecular
structure of amino acids and the polypeptide chains of proteins or possibly divided between him and Kendrew and Perutz. On
the other hand, I think that it might well be premature to make an award of a Prize to Watson and Crick, because of existing
uncertainty about the detailed structure of nucleic acid. I myself feel that it is likely that the general nature of the
Watson-Crick structure is correct, but that there is doubt about details.
With respect to Wilkins, I may say that I recognize his virtuosity in having grown better fibers of DNA than any that had
been grown before and in having obtained x-ray photographs than were available before, but I doubt that this works represents
a sufficient contribution to chemistry to permit him to be included among recipients of a Nobel Prize.
Wile [sic] I am discussing these matters, I should like to say that I regret that both W. M. Latimer and W. H. Rodebush are
now dead, and that the recognition of the great importance of the hydrogen bond in molecules of living organisms (proteins
and nucleic acids) as well as in simple substances was delayed until recently. Their discovery of the hydrogen bond, announced
in the Journal of the American Chemical Society 42, 1419 (1920), can now be seen to be justified as the basis for the award
of a Nobel Prize in Chemistry to them.
Sincerely yours,
Linus Pauling:jh
Enclosures
cc: Nobel Committee for Physics, Nobel Committee for Chemistry, Professor Sir Lawrence Bragg
