Requirements for activation of trypsinogen and chymotrypsinogen in rabbit pancreatic juice

✍ Scribed by Geoffrey Glazer; Michael L. Steer

• Publisher: Elsevier Science
• Year: 1977
• Tongue: English
• Weight: 685 KB
• Volume: 77
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(77)90297-4

✦ Synopsis

Requirements for the activation of trypsinogen and chymotrypsinogen in rabbit pancreatic juice are described. Trypsinogen is optimally activated by purified enterokinase at 30°C after 2 hr in the presence of 25 mM Tris-HCI, pH 8.1, containing 25 mM CaCl,. Chymotrypsinogen is optimally activated by trypsin at 4°C after 2 hr in the presence of 50 mM Tris-HCI, pH 8.1. Bovine serum albumin is added to the activation mixtures to prevent loss of zymogens through adsorption to the container walls. The activation of trypsinogen by purified enterokinase is found to vary with temperature, time, Ca2+ concentration, and enterokinase concentration but is unchanged over the pH range of 7.4-8.8. Activation of chymotrypsinogen by trypsin is found to vary with temperature, time, and trypsin concentration but is not altered by the presence or absence of Ca2+ and is unchanged over the pH range of 7.4-8.8. Using optimal conditions for zymogen activation, the eventual proteolytic activity and the amount of juice protein being activated are directly related. Deviations from these conditions of activation could lead to erroneous results.