JOHN KENDREW (1917 - 1997). A Three-Dimensional Model of the Myoglobin Molecule Obtained by X-Ray Analysis. (Nature 1958, 181, 662-666.)

Kendrew's discovery was one of the greatest achievements in the history of molecular biology. The structures of proteins are the key to their biological function. Protein molecules, however, contain at minimum thousands of atoms, and in the 1940s the intricacies of the three-dimensional structure of proteins were too complex for analysis by conventional X-ray crystallography, because the process of carrying out the needed calculations by slide-rules and electric calculators was far too slow.

By the late 1940s, when Kendrew joined the Cavendish Laboratory as a graduate student, new and more sophisticated tools for attacking the problem became available. The first of these tools was the technique of isomorphous replacement, developed by Perutz during his own researches on hemoglobin, in which certain light atoms in a protein crystal are replaced with heavy atoms that provide a frame of reference for comparing diffraction patterns. The second tool was the electronic computer, developed during World War II, which Kendrew introduced to computational biology in 1951. In 1951 Cambridge University was one of only three or four places in the world with a high-speed stored-program electronic computer, and Kendrew took full advantage of the speed of Cambridge's EDSAC computer, and its more powerful successors, to execute the complex mathematical calculations required to solve the structure of myoglobin.

Nevertheless, even with the EDSAC computer performing the calculations, it took Kendrew and his team until the summer of 1957 before they were able to succeed in creating a three-dimensional map of myoglobin at the so-called 'low resolution' of 6 angstroms. The map was blurry, but still sufficient to show the relative locations of the polypeptide chains, and the iron atom and its associated porphyrin ring. The most striking features of the molecule were its irregularity and its total lack of symmetry.

The 6-angstrom resolution was too low to show the molecule's finer features, but by 1960 Kendrew and his team were able to obtain a map of the molecule at 2-angstrom resolution. Today, thousands of scientists work on determining the structures of proteins, using the methods that Kendrew and Perutz pioneered.

Jeremy Norman, "The First Solution of the Three-Dimensional Molecular Structure of a Protein (1958 - 1960),", accessed 5 Jan 2012.

List of books in exhibit (links go to author information and references)