Journal of Biosciences

, Volume 8, Issue 1–2, pp 45–55 | Cite as

X-ray studies of water structure in 2 Zn insulin crystal

  • Noriyoshi Sakabe
  • Kiwako Sakabe
  • Kyoyu Sasaki


The water structure of rhombohedral 2 Zn insulin crystal which contains about 280 water molecules and 0.55-0.60 mol citrate molecules per dimer has been studied by X-ray crystallographic refinement with 1.1 A resolution data. Atomic parameters of 83 fully occupied and 258 partially occupied water molecules and 0.3 mol of citrate were obtained. Full matrix least-squares method with isotropic temperature factor was used for the refinement of partially occupied water molecules. The water molecules in this crystal exist in one of the three states: fully occupied water, partially occupied water and water continuum, and a schematic model of water structure in protein crystal was proposed. The flexibility of water molecules is described.

Key words

X-ray analysis water structure in protein crystal 2 Zn insulin crystal fully matrix least-squares refinement disordered water 

Abbreviation used


Nuclear magnetic resonance


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Agarwal, R. C. (1978)Acta Crystallogr. sect. A,34, 791.CrossRefGoogle Scholar
  2. Blake, C. C. F., Pulford, W. C. A. and Artymiuk, P. J. (1983)J. Mol. Biol.,167, 693.CrossRefGoogle Scholar
  3. Dodson, E. J., Isaacs, N. W. and Rollet, J. S. (1976)Acta Crystallogr. sect. A,32, 311.CrossRefGoogle Scholar
  4. Edsall, J. T. and Mackenzie, H. A. (1983)Annu. Rev. Biophys., (ed. M. Kotani) (Tokyo: Japan Sci. Soc. Press) p. 53.Google Scholar
  5. Matthews, B. W. (1976)Annu. Rev. Phys. Chem.,27, 493.CrossRefGoogle Scholar
  6. Nagashima, N., Suzuki, E. and Tsuboi, M. (1984)Bull. Chem. Soc. Jpn.,57, 1409.CrossRefGoogle Scholar
  7. Sakabe, N., Sakabe, K. and Sasaki, K. (1978)Pro Insulin, Insulin and C peptide (eds S. Baba, T. Kaneko and N. Yanaihara) (Amsterdam: Excepta Medica) p. 73.Google Scholar
  8. Sakabe, K., Sakabe, N. and Sasaki, K. (1980)Water and Metal Cations in Biological Systems (eds B. Pullman and K. Yagi) (Tokyo: Japan Sci. Soc. Press) p. 117.Google Scholar
  9. Sakabe, N., Sakabe, K. and Sasaki, K. (1981)Structure Studies on Molecules of Biological Interest (eds G. Dodson, J. P. Glusker and D. Sayre) (Oxford: Clarendon Press).Google Scholar
  10. Sakabe, N., Sasaki, K. and Sakabe, K. (1984)Methods and Applications in crystallographic Computing (eds S. R. Hall and T. Ashida) (Oxford: Clarendon Press) p. 273.Google Scholar
  11. Sielecki, A. R. and James, M. N. G. (1981) inRefinement of Protein Structures (eds J. W. Machin, P. A. Campbell and M. Elder) (Warrington: Daresbury Laboratory) p. 78.Google Scholar
  12. Wang, D., Chang, W. and Dai, J. (1982)Sci. Sin. (Series B),25, 711.Google Scholar
  13. Watenpaugh, K. D., Margulis, T. N., Sieker, L. C. and Jensen, L. H. (1978)J. Mol. Biol.,122, 175.CrossRefGoogle Scholar

Copyright information

© Indian Academy of Sciences 1985

Authors and Affiliations

  • Noriyoshi Sakabe
    • 1
  • Kiwako Sakabe
    • 1
  • Kyoyu Sasaki
    • 2
  1. 1.Department of Chemistry, Faculty of ScienceNagoya UniversityNagoyaJapan
  2. 2.College of Medical TechnologyNagoya UniversityNagoyaJapan

Personalised recommendations