Page 106 - Color Atlas of Biochemistry

Enzymes 97

A. Types of inhibitor

Competitive 1. Uninhibited Noncompetitive

I
C I C C C C C

C C C
a
4. Modifying reagent

Allosteric
C I C C C
I

C C
b a

2. Substrate analogs
I

C I C v C C
I I

C
C
b
[A]
3. Transition state 6. 5. “Suicide substrate”
analog

B. Kinetics of inhibition

Competitive Maximal
inhibition:
10 V unchanged velocity V 10

8
8
Velocity v (nkat) 6 Non- Slope = K m 6 Velocity v (nkat)

competitive
4
inhibition:
V reduced 4
2 2
K m
increased
K m
unchanged
0 0
0 10 20 80 90 100 0.0 0.5 1.0 1.5 2.0
–o
Substrate concentration [A] (mM) v/[A] (nkat · mM )
1. Hyperbolic plot 2. Eadie Hofstee plot

Koolman, Color Atlas of Biochemistry, 2nd edition © 2005 Thieme
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