Don Caspar on Working with Jim Watson
  Don Caspar     Biography    
Recorded: 01 Jan 2001

… one of the sort of influential things that he got involved with during the period that Bragg had called a moratorium on work on DNA structure in Cambridge, was tobacco mosaic virus that Francis had taught Jim how to interpret helix—helical diffraction pattern and [J.D.] Bernal and [Isidore] Fankuchen had obtained some really quite spectacular results with their experimental studies in balcima starting in 1930, ’36—an important paper was published in, well, I guess just before the war in 1941. But, [J.D.] Bernal who was, you know, considered the brightest, one of the brightest intellects in British science in the 1930s, that he couldn’t see the helix in TMV, but helices were not fashionable then… But in any case, Jim recognized the helical symmetry but he got the symmetry wrong. And I was not very interested in using radiation to inactivate biological structures, but I had gotten, actually I had gotten introduced to X-ray diffraction by Fankuchen who had been a family friend when… I knew him from the time I was three years old and he had introduced me to X-ray crystallography in 1947 just after I got out of the army. And then I had started to do some work on a small angle X-ray scattering and realized that tobacco mosaic virus that it was much more [a] prospect of getting more detailed information with oriented specimens, so it was just around that time that Jim had published. Well, actually, I heard the work before it was published from Jim’s visits and I also heard about Rosalind Franklin and the fact that she was also starting to work on tobacco mosaic virus. So, in any case, you know, I had completed my experimental work in 1954 and then went to Caltech and sort of among other things, was working with Jim to try to interpret the results that I had gotten on the radial electron density distribution in TMV and we wrote a paper where we completely misinterpreted the RNA structure and that was—let’s see, it would have been 1955, but we had sent a copy of the paper to Rosalind Franklin and she had just done sort of critical experiment of determining the radial distribution of the structure of the ribonuclease protein without the nucleic acid which proved that our model was completely wrong. So that paper, fortunately, never got published.

Donald Caspar, structural biologist and crystallographer, is a professor emeritus of Biological Sciences at the Institute of Molecular Biophysics at Florida State University in Tallahassee, Florida and is also a member of the National Academy of Sciences.

Born on January 8, 1927, he received his B.A. in Physics from Cornell University in 1950, and his his Ph.D. in Biophysics from Yale University in 1955. Caspar is interested in protein adaptability, virus assembly, protein plasticity and x-ray diffraction. He currently researches the mechanics of protein movements by executing structural studies.

He has attended many symposia at Cold Spring Harbor Laboratory, starting in 1961, and worked with Watson at Caltech and Harvard. He is a member of the National Academy of Science. Dr. Casper is a long-time friend and colleague of Dr. James D. Watson as well as many of the early pioneers in molecular biology, including Dr. Rosalind Franklin.