2.4.2.18	dilution inactivates	
2.4.2.18	freezing and thawing inactivates	
2.4.2.18	glycerol, 10%, is essential for storage, but it must be replaced by polyethylene glycol to achieve crystals that are not severely temperature dependent and radiation sensitive	
2.4.2.18	the enzyme is either digested by trypsin, V8-protease or thermolysin after incubation for 1 h at 25°C but not by thermolysin at 70°C