18 December 1953

Professor Vincent du Vigneaud

Cornell University Medical School

1300 York Avenue

New York 21, N.Y.

Dear Vincent:

I have been very interested to read about your synthesis of an octapeptide amide with the hormonal activity of oxytocin and very probably identical with it.

These substances interest us very much, because of our desire to make complete x-ray structure determinations of peptides, and especially peptides with physiological activity.

I suppose that it is doubtful that you have oxytocin in crystals as large as a tenth of a millimeter. If you have, we should like very much to attempt to carry out a complete structure determination of this substance. It would be a colossal job, but nevertheless we think that it would be worth while to try.

Of the other substances mentioned in your communication there is one, L-glutaminyl-L-asparagine, that interests us greatly. Would it be possible for you to give us a small amount of this material, which we could attempt to crystallize and to investigate with x-rays? If you have crystals already, that would be best of all; if not, a hundred milligrams, say, of the preparation would permit the workers here to begin the job.

With best wishes to you for the holiday season, I am

Sincerely yours,

Linus Pauling:W