All rights reserved. Terms of use. Â¨ 37 11 Thermodynamics andThermochemistry Thermodynamics is the study of heat, and how heat can be interconverted into other energyforms. In thermodynamics the system is a specific part of the universe that is being studied,often the system is a chemical reaction. The surroundings are all parts of the universe that arenot the system, typically everything outside the test tube.Â¥ An open system can exchange both energy and matter with its surroundings.
Pepsin is commonly used in the preparation of F(ab')2 fragments from antibodies. In some assays it is preferable to use only the antigen binding (Fab) portion of the antibody. For these applications, antibodies may be enzymatically digested to produce either an Fab or an F(ab')2 fragment of the antibody.
8. For general digestion of proteins, suggested conditions are a 0.4% solution of pepsin in 10 mM HCl, and digestion for 30-90 minutes at 37 Â°C. Pepsin has optimal activity with native proteins at approximately pH 1.0, but with some denatured proteins the optimal activity is at approximately pH 1.5-3.5.9,10.inetics, Solubility and Solution Stability. Pepsin is soluble in deionized water at 1% (10 mg/ml) and at 0.4% (4 mg/ml) in cold 10 mM hydrochloric acid. Solutions at pH 4.4 are stable at -20 Â°C for about 2-3 months. 12 The pH optimum for activity for porcine pepsin is ~2.2.