Premium
ARGINASE STUDIES.—I. THE RELATION BETWEEN THE ACTIVITY OF THE ENZYME AND THE CONCENTRATION OF HYDROGEN IONS
Author(s) -
Hunter Andrew,
Morrell Joseph A.
Publication year - 1933
Publication title -
quarterly journal of experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0370-2901
DOI - 10.1113/expphysiol.1933.sp000618
Subject(s) - arginase , titration curve , substrate (aquarium) , enzyme assay , chemistry , enzyme , titration , hydrogen ion , activity coefficient , ion , biochemistry , inorganic chemistry , biophysics , chromatography , biology , organic chemistry , amino acid , arginine , aqueous solution , ecology
1. The range of pH over which arginase exerts a measurable activity is 4–8 to 1l·5. 2. The point of maximum activity is at or near pH 9·8. 3. The pH activity curve is therefore strikingly unsymmetrical. 4. In the alkaline range of its activity, beginning at about pH 8, the enzyme, even in the presence of its substrate, undergoes increasingly rapid destruction. 5. This accounts in all probability for the very rapid fall of activity on the alkaline side of the optimum. 6. The rising limb of the activity curve is not a simple symmetrical S‐shaped curve, but has a complex form, closely resembling the titration curves of certain proteins. 7. The possible interpretation to be put upon this observation is briefly discussed.