The Contribution of the Japanese team; Neutron diffraction experiment of fully deuterated proteins, such as RNase A, insulin, myoglobin and so on

Niimura, Nobuo*; Tanaka, Ichiro*; Onishi, Yuki*; Ostermann, A.*; Kurihara, Kazuo; Honjo, Eijiro; Kuroki, Ryota; Futami, Junichiro*; Yamada, Hidenori*

Our goal is to develop new methods for determining macromolecular crystal structures from neutron diffraction data and to validate these methods by making applications to several proteins. The proposed methods, which have the potential to be more powerful than X-ray ones, exploit perfectly isomorphous pairs of crystals that differ by replacement of D atoms with H atoms in selected amino-acid residues. This research involves collaboration among teams on three continents that have expertise in different aspects of neutron crystallography. The Japanese team measures high-resolution neutron diffraction data from protein crystals to answer questions about H bonding, protonation, hydration, and enzyme mechanisms. The team will focus on fundamental and simple proteins such as myoglobin, insulin, and RNase A at the first stage and then on rubredoxin, aldose reductase and other samples from the French team. In the meeting the research plan of the Japanese team will be reported.