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Structural changes in the activation of chymotrypsinogen and trypsinogen. Effect of urea on chymotrypsinogen and delta-chymotrypsin

1956; Elsevier BV; Volume: 65; Issue: 1 Linguagem: Inglês

10.1016/0003-9861(56)90191-6

1096-0384

Hans Neurath, John A. Rupley, William J. Dreyer,

Viral Infectious Diseases and Gene Expression in Insects

In an attempt to detect structural differences between chymotrypsinogen and chymotrypsin, and trypsinogen and trypsin, measurements of the optical rotation and of the enzymatic activity of these proteins were carried out. The results indicate that the decrease in specific levorotation on activation of these zymogens is correlated with the appearance of enzymatic activity, and that the structure of the active enzyme is more sensitive to pH changes than that of the zymogen. Measurements of the effect of urea on optical rotation, viscosity, and biological activity of chymotrypsinogen and δ-chymotrypsin are also reported in this communication. These include the effects of time and urea concentration on the measured parameters. On the basis of the data presented, in conjunction with other information on the chemical and physical characteristics of chymotrypsinogen and δ-chymotrypsin, tentative conclusions have been drawn concerning the structural changes involved in activation and denaturation, respectively.