December 28, 1951

Mr. Henry Allen Moe

John Simon Guggenheim Memorial

Foundation

551 Fifth Avenue

New York 17, N.Y.

Dear Henry:

Thanks very much for your Christmas letter. Also, Ava Helen and I were happy to have the Christmas card that you and Edith sent us. We have not sent out any cards for several years, because of our being so busy, especially along before Christmas.

I am sorry that you have been laid up with the flu. Should you not be getting another man in the office, to help you out - and especially to be available, together with Jim, when you take your sabbatical year?

I shall look forward to receiving the batch of new-type cases, and also some of the 1952 digests. I thank you for the honorarium, which surprised me when it arrived last week. You know that I am glad to do anything that I can for you and the Foundation.

We have three of the children at home with us for the holidays, along with two (at times three) other young people - friends of Linda down from Reed College. Ava Helen and I are feeling well, but I think that she is being kept too busy, by the house full of people.

Tomorrow we are going down to the beach to collect marine animals, in order that I may prepare some specimens of muscle protein. An extraordinary situation has arisen. Twenty-five years ago some investigators in Germany dried a piece of muscle and made an x-ray photograph of it; this had been done scores of times before, and the x-ray photographs that had been obtained had always been the same - rather fuzzy, uninteresting diagrams - but this preparation gave a striking photograph, such as is obtained from a crystalline material. A similar crystalline photograph was obtained from another preparation in Switzerland ten years ago, and Bear, in Schmitt's laboratory, has made two samples of muscle that give the crystalline pattern. Corey and I discussed the photographed obtained by the Swiss workers, and described their sample as crystallized muscle. Bear published a letter in Nature last month, in which he states that he does not think that the crystalline material is muscle at all. It is hard to imagine what he thinks it is, because it is evident that the crystalline material makes up most of the sample, which was just a piece of muscle that had been dried. Corey and I feel that this crystalline pattern is extremely important, because of the large amount of information that it probably will provide (and in part already has provided) about the struc-

ture of proteins, and even about the nature of the phenomenon of muscular contraction. We have the original sample of the Swiss investigators, Lotmar and Picken(Picken is an Englishman), but it no longer is crystalline - instead it gives the ordinary fuzzy muscle diffraction pattern.

I estimate that some hundreds of samples of dried muscle have been made by investigators during the past thirty years and subjected to x-ray diffraction. Four of these samples have turned out to be crystalline. Nobody knows what the conditions are that produce the crystalline material. Accordingly I propose to make some hundreds of samples of dried muscle, in various ways, and to make x-ray photographs of all of then, with the expectation that in a month, or two months, or three months, or perhaps six months a sample of crystalline muscle will turn up. He can then make better x-ray photographs than have been obtained by the earlier investigators, and presumably derive some valuable information about protein structure and muscle structure from them. The four samples of crystallized muscle that were obtained by earlier investigators are from four different animals - frog, mussel, pectin, and squid. These are all cold blooded animals, and accordingly we are planning to get samples of muscle form cold blooded animals to begin with, and to try some mammalian muscle samples later on.

The Royal Society is arranging a Conference on Protein Structure. I stated at first that I could not attend, because of the trip around the world. Now I have agreed to attend, and the date has been set for May 1, rather than April 24, in order to permit me to come to the Philosophical Society meeting and then to attend the Conference. Ava Helen and I are now planning to go to the Conference, and to take a vacation during May and June, and then to attend an International Conference on Biochemistry in July, which is to be held in Paris. We shall then come back home, about August 1.

With best wishes to you and Edith for the New Year, I am

Sincerely yours,

Linus Pauling:W