The Differentiation of Two Forms of Chymotrypsin by Their Rates of Urea Denaturation

Abstract

SUMMARY From studies of the kinetics of urea denaturation it is possible to distinguish between the 6 and (Y forms of chymotrypsin. The results indicate that the enzymic conversions of chymotryp- sinogen to 7~ or d-chymotrypsin and to cr-chymotrypsin are accompanied by changes in conformation. The stability of chymotrypsinogen in urea solutions is intermediate between that of the two forms of chymotrypsin. REFERENCES 1. CHERVENKA, C. H., J. Am. Chem. Sot., 82, 582 (1960). 2. NORTHRUP, J. H., KUNITZ, M., AND HERRIOTT, R. M., Crystal- line enzymes, Ed. 2, Columbia University Press, New York, 1948, p. 96. 3. WILCOX, P. E., COHEN, AND TAN, W., J. Biol. Chem., 228, 999 (1957). 4. SCHWERT, G. W., AND TAKENAKA, Y., Biochim. et Biophys. Acta, 16, 570 (1955). 5. LEVY, M., AND BENAGLIA, A. E., J. Biol. Chem., 186,829 (1950). 6. JACOBSEN, C. F., Compt. rend. trav. lab. Carlsberg Ser. chim., 26, 325 (1947). 7. FROST, A. A., AND PEARSON, R. G., Kinetics and mechanism, John Wiley’and Sons, Inc.; New York, 1958, p. 147. ’ 8. Wu. F. C.. AND LASKOWSKI. M.. Biochim. et Biowhus. Acta. 16, 110 (1956). I I . - 9. GREEN, N. M., GLADNER J. A., CUNNINGHAM, L. W.,