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
