NEUTRON LAUE DIFFRACTOMETRY WITH AN IMAGING PLATE PROVIDES AN EFFECTIVE DATA-COLLECTION FOR NEUTRON PROTEIN CRYSTALLOGRAPHY

Neutron Laue diffraction 2 Angstrom data from tetragonal hen egg-white (HEW) lysozyme were collected for 10 days with neutron imaging plates . All the 960 hydrogen atoms in the lysozyme and 157 bound water molec ules could be identified. The final R-factor is 19.5%. Several interes ting features of hydrogen atoms and bound water molecules of HEW-lysoz yme were found as follows. (1) The crystal was grown at pH 7.0. There are no hydrogen (deuterium) atoms bound to carboxylate oxygen atoms of Glu35 and Asp52, which explains why lysozyme is less active at pH 7.0 . (2) Hydrogen atoms and deuterium atoms are clearly identified. As an example, the omit map around indol ring of Trp 111 is shown. (C) 1998 Elsevier Science B.V. All rights reserved.