Papain used for this purpose was crude preparations from Tokyo Kasei
Kogyo Co.. To 20 g of minced cock breast muscle was added 0.46 g of
papain in 10 ml of the activating medium described above and thoroughly
mixed with 2 mM (final conc.)NaNs. The mixture was incubated for specified
periods of time at 2°C and the reaction was stopped by the addition of
2 mM (final cone.) monoiodoacetic acid. The reaction mixture which contained
10 ml of H20 instead of papain solution, served as control (O-hr sample).
The activity of all papain preparations used in this study was monitored
by using rate of splitting 1% casein as a substrate per 1 min15). Purified
preparations from Sigma and crude preparations from Tokyo Kasei Kogyo
had activities of approximately 0.69 mg and 10.75 mg casein units, respectively.