ATP is a (+) allosteric effector, and CTP is a (-) allosteric effector of theenzyme ATCase. Both of these heterotropic effectors bind to the regulatorysubunits on ATCase. The substrates of ATCase, aspartate and carbamoylphosphate, bind the enzyme active site with positive cooperativity (i.e.,they exert a “+” homotropic effect on activity). As the concentrations ofthe substrates change from values where [S] ≪ KM to values where [S] issaturating ([S]≫ KM), how will the binding constants for each of the twoallosteric effectors change? In other words, does ATP bind ATCase withhigher affinity when [S] is low or high? Does CTP bind ATCase with higheraffinity when [S] is low or high?

ATP is a (+) allosteric effector, and CTP is a (-) allosteric effector of theenzyme ATCase. Both of these heterotropic effectors bind to the regulatorysubunits on ATCase. The substrates of ATCase, aspartate and carbamoylphosphate, bind the enzyme active site with positive cooperativity (i.e.,they exert a “+” homotropic effect on activity). As the concentrations ofthe substrates change from values where [S] ≪ KM to values where [S] issaturating ([S]≫ KM), how will the binding constants for each of the twoallosteric effectors change? In other words, does ATP bind ATCase withhigher affinity when [S] is low or high? Does CTP bind ATCase with higheraffinity when [S] is low or high?

Biochemistry

6th Edition

ISBN:9781305577206

Author:Reginald H. Garrett, Charles M. Grisham

Publisher:Reginald H. Garrett, Charles M. Grisham

Chapter23: Fatty Acid Catabolism

Section: Chapter Questions

Problem 21P: Using the ActiveModel for enoyl-CoA dehydratase, give an example of a case in which conserved...

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