Crystallization of porcine pancreatic elastase and a preliminary neutron diffraction experiment

Kinoshita, Takayoshi*; Tamada, Taro; Imai, Keisuke*; Kurihara, Kazuo; Ohara, Takashi   ; Kuroki, Ryota

Porcine pancreatic elastase (PPE) resembles the attractive drug target leukocyte elastase, which has been implicated in a number of inflammatory disorders. In order to investigate the structural characteristics of the covalent inhibitor bound to PPE, including hydrogen and hydration of water, a single crystal of PPE for neutron diffraction study was grown in DO containing 0.2 M sodium sulfate (pD=5.0) using the sitting-drop vapor diffusion method. The crystal was grown to a size of 1.6 mm by repeated macro-seeding. The neutron diffraction data were collected at room temperature using a BIX-3 diffractometer at the JRR-3 research reactor of the Japan Atomic Energy Agency (JAEA). The data set was integrated and scaled to 2.3 resolution with space group P212121 and cell dimensions of a=51.2, b=57.8 and c=75.6.