Inhibition Modality in Bisubstrate Reactions

The modality of compounds that inhibit enzymes catalyzing bisubstrate reactions will differ with respect to the two substrates of the reaction, and the pattern of inhibition will depend on the reaction mechanism of the enzyme. Thus, when we use terms like competitive, noncompetitive, or uncompetitive inhibition, we must 

The example of methotrexate points out that the inhibition modality of dead end inhibitors, with respect to a specific substrate, will depend on the reaction mechanism of the target enzyme. Thus a complete understanding of inhibition mechanism requires an understanding of the underlying reaction mechanism of the target enzyme. A comprehensive discussion of these issues has been provided by Segel (1975). Table 3.6 summarizes the pattern of dead-end inhibition observed for competitive inhibitors of one substrate in the common bisubstrate reaction mecha- 

Reaction Mechanism Competitive Inhibitor for Substrate Inhibition Pattern Observed  

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