CRYSTALLINE TRYPSIN
Open Access
- 20 November 1932
- journal article
- research article
- Published by Rockefeller University Press in The Journal of general physiology
- Vol. 16 (2), 339-348
- https://doi.org/10.1085/jgp.16.2.339
Abstract
The rate of digestion, as determined by the increase in non-protein nitrogen or formol titration, of casein, gelatin, and hemoglobin with crystalline trypsin preparations increases nearly in proportion to the concentration of protein, but with crude pancreatic extract the rate of digestion becomes independent of the protein concentration in concentrations of more than 2.5 per cent. With both enzymes the rate of digestion of mixtures of 5 per cent casein and gelatin is greater than would be expected from the point of view of a compound between enzyme and substrate. The rate of digestion of 5 per cent casein in the presence of 5 per cent gelatin is exactly the same as that of 5 per cent casein alone. This result is obtained with both enzymes. The digestion of casein with crude trypsin follows the course of a monomolecular reaction quite closely while with purified trypsin the velocity constant decreases as the reaction proceeds. In the case of hemoglobin the monomolecular velocity constant decreases with both purified and crude enzyme. When the reaction is followed by changes in the viscosity of the solution the abnormal effect of changing substrate concentration disappears and the reaction is in fair agreement with the monomolecular equation. The results as a whole indicate that the abnormalities of the reaction are due to the occurrence of several consecutive reactions rather than to the formation of a substrate enzyme compound.This publication has 2 references indexed in Scilit:
- THE EFFECT OF ENZYME PURITY ON THE KINETICS OF TRYPTIC HYDROLYSISThe Journal of general physiology, 1926
- AN EMPIRICAL FORMULA FOR THE RELATION BETWEEN VISCOSITY OF SOLUTION AND VOLUME OF SOLUTEThe Journal of general physiology, 1926