Page 22

Enzymatic Inhibition

Cleland's Rules

1 Competitive I and S compete for the same form of the enzyme or with forms separated only by reversible steps.
2 Uncompetitive I combines with a form of E which is not responsible for the uptake of S. (In general, I combines somewhere AFTER the addition of S.)
3 Non-competitive a combination of the above two types

Overall reaction:
A + B P + Q

Inhibitor form Variable A Variable B
EAI Uncompetitive Competitive
EQI Uncompetitive Uncompetitive
EI Competitive Non-competitive
EQPI Non-competitive Non-competitive

1	Competitive	I and S compete for the same form of the enzyme or with forms separated only by reversible steps.
2	Uncompetitive	I combines with a form of E which is not responsible for the uptake of S. (In general, I combines somewhere AFTER the addition of S.)
3	Non-competitive	a combination of the above two types