The Crystal Structure of Rhombohedral 2 Zinc Insulin (original) (raw)

1. T. L. Blundell,
2. J. F. Cutfield,
3. E. J. Dodson,
4. G. G. Dodson,
5. D. C. Hodgkin, and
6. D. A. Mercola
7. Laboratory of Molecular Biophysics, Oxford University, Oxford, England

Excerpt

In the latter half of 1969 the interpretation of an electron-density map at 2.8 Å resolution of rhombohedral 2 zinc insulin (porcine) was presented (Adams et al., 1969). A more thorough analysis of this map has led to some small changes in the original structure though the overall organization remains unchanged. Coordinates for all the atoms in the two independent molecules have been derived (Blundell et al., 1971a).

Initially atomic coordinates were obtained from a model built using the Richards' optical superposition device and as such were only an approximate set. These were subsequently modified with the help of computer programs written by R. Diamond (1966) and M. Levitt (unpublished), the former imposing correct molecular geometry and the latter minimizing the energy of interatomic interactions. The programs produced atomic coordinates which differed slightly from one another and which, not unexpectedly, sometimes deviated from the electron density. A third, compromise set