Abstract
Protonation states determination by neutron (2.2 Å at room temperature) and X-ray (0.66 Å at 100 K) crystallographic studies were compared for a medium size enzyme, human aldose reductase (MW = 36 kDa), complexed with its NADP+ coenzyme and a selected inhibitor of therapeutic interest. The neutron resolution could be achieved only with the ab initio fully deuterated protein and the subsequent crystallization in D 2O of the complex. We used the largest good-quality crystal (1.00 × 0.67 × 0.23 mm, i.e. volume of 0.15 mm3) that we were able to grow so far. Both studies enable the determination of protonation states, with a clear advantage for neutrons in the case of less-ordered atoms (B > 5 Å2). Hydrogen atoms are best determined by a complementary analysis of the Fourier maps obtained from both methods.
| Original language | English |
|---|---|
| Pages (from-to) | 577-583 |
| Number of pages | 7 |
| Journal | European Biophysics Journal |
| Volume | 35 |
| Issue number | 7 |
| DOIs | |
| State | Published - Sep 2006 |
Funding
Acknowledgements We thank the staff of the EMBL and ILL, Grenoble, France and of the SBC, APS, Argonne, USA, for their help in data collection, and of the IGBMC for their support. This work was supported by the Centre National de la Recherché Sci-entifique (CNRS), by the CNRS-DFG collaboration (CERC3), by the Institut National de la Santé et de la Recherché Médicale and the Hôpital Universitaire de Strasbourg (H.U.S).