The role of freezing in trypsin activity oscillations.

The importance of the frozen phase in the formation of cryooscillations of trypsin activity has been shown in experiments conducted at -10 degrees C under frozen and supercooled conditions, respectively. A solution containing trypsin obtained by trypsinogen activation and 0.1 M MnCl2 was distributed in test tubes with or without previous freezing and kept at -10 degrees C and pH 8.4. At given time intervals the frozen and supercooled samples were tested simultaneously for tryptic activity. Although a temporal motion of trypsin activity was produced by the frozen samples, the activity of the supercooled samples began to oscillate only after spontaneous freezing of the solutions. This phenomenon suggests the importance of compartmentalization of the frozen heterogeneous system, which results in an increase in concentration vs a decrease in diffusion rate of the components.