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Updated: Aug 3, 2026

The Importance of Correct Protein Concentration for Kinetics and Affinity Determination in Structure-function Analysis
Published on: March 17, 2010
The effect of pH on the kinetics of arylsulphatases A and B
Abstract:
The effect of pH on the kinetics of rat liver arylsulphatases A and B is very similar and shows that two groups with pK values of 4.4-4.5 and 5.7-5.8 are important for enzyme activity. Substrate binding has no effect on the group with a pK of 4.4-4.5; however, the pK of the second group is shifted to 7.1-7.5 in the enzyme-substrate complex. An analysis of the effect of pH on the Ki for sulphate inhibition suggests that HSO4-is the true product. A model is proposed that involves the two ionizing groups identified in the present study in a concerted general acid-base-catalysed mechanism.
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