94305

November 5, 1969

Dr. Anthony C. Allison

Clinical Research Center Laboratories

National Institute for Medical Research

Milhill, N.W. 7, London, England

Dear Dr. Allison:

I was pleased to hear from you. Note that I am at Stanford University now.

The idea that sickle cell anemia was a disease of the hemoglobin molecules had not occurred to me when I heard that the cells were birefringent. Instead, it was the statement by Dr. Castle, when we were having dinner with a few other people, that the cells are sickled in the venous blood but not in the arterial blood that caused me to decide immediately that it was a molecular disease, and that the hemoglobin molecules were self-complementary, so that they would combine to form long rods, which would then crystallize and form the red cells. I did not learn about the birefringence of sickled cells until later.

I am sending separately some of my reprints, including a list of my papers. I think that I described the discovery of sickle cell anemia hemoglobin in paper 271 and paper 257, page 902 of the List of Scientific Publications.

I am sure that I have published an account of the discovery of the alpha helix, but I do not remember where. I spent the summer of 1937 in an effort to develop a way of folding the polypeptide chain that would account for the X-ray pattern of hair, but without success. In the spring of 1948, when I was George Eastman Professor at Oxford, I was in bed with a cold for a few days. I began thinking about the problem, and decided to look for helical hydrogen-bonded structures, with planar amide groups, and all residues structurally equivalent. Within a few hours I had discovered a couple of these structures. Neither one seemed to agree with the X-ray pattern, however, and I did not publish anything about them for more than a year.

You may be interested in my work on anesthesia. The development of the hydrate microcrystal theory is described in my paper number 338, page 903. I do not have extra copies at hand.

It was a pleasure to hear from you again.

Sincerely,

LP/mdm

Linus Pauling