PROTEIN CRYSTALLOGRAPHY AND COMPUTING: RECOLLECTIONS OF THE 50s. John Kendrew, The Old Guild Hall, 4 Church Lane, Linton Cambridge, CB1 6JX UK

The 50s were the golden age of basic science, and especially of biology; crystallography, which advanced rapidly during those years, played a major role in this. Our work in Cambridge on the structures of proteins and DNA owed a great deal to good luck and indeed to accidents. With the exception of Jim Watson none of the members of our early group were trained as biologists - or indeed as crystallographers: Max Perutz and I began as chemists and Francis Crick as a physicist. On the protein side Max and I thought that to solve the structure of proteins was the most important problem in biology (this was before the importance of DNA was realised), and that crystallography was the most hopeful method. Until I began the work in 1946 I had never done a course in X-ray crystallography and had to learn at least a little about the subject as I went along. Another piece of good luck was that the Medical Research Council supported us generously for more than ten years during which there were no results and only a few incorrect papers: could it happen today? Several technical advances were very important; the first rotating anode x-ray tubes (ours was home-made in the Cavendish workshop); and the first densitometer suitable for measuring intensities. Finally there was the electronic computer. The first Cambridge computer was EDSAC I, using thermionic valves and with a store of only 512 words; it began to operate in the early 50s. I was the first member of the group to use it seriously, stimulated by my student Hugh Huxley, so I had to learn programming as well as crystallography; and programming had to be done in machine language because Fortran had not yet been invented. And of course had the computer arrived ten years later the structures would have only come out ten years later - computing by hand methods would have been quite impracticable. So the timely arrival of EDSAC was also a piece of luck for us. Or was it luck?

When my 6 Angstrom model of myoglobin came out one of the first people to see it was Desmond Bernal, one of the gurus of molecular biology and a man so wise that everyone called him Sage; when he saw it he said "I always knew proteins would look like that". What did he mean and how did he know?

And when we got the 2 Angstrom structure we had to build the models with steel rods; we had no computer graphics. Looking back on those times from today makes one feel nostalgic and the methods we used seem now very primitive; but it was great fun.