Enzyme Inhibition
Inhibitors
substance that reduces activity of enzymeby binding to it in
some way
combines with enzyme in way that influences binding of
substrate Ellor turnover number
Inhibitors ND understanding functionality of enzyme
Affect V Max hence affect enzyme activity
May resemble substrate structurally
can compete with sub for active rite
ManyDrugs inhibitors that block action ofspecific enzyme
Reversible vs irreversible
weakbindinginteractions inhibitor remainsboundto enzyme
non covalentinteractions strong covalentinteractions
Hbonds bind to residues AAsidechains
Hydrophobic a prosthetic
groups otherthanA
v d Waals eg Hernegrouponhaemoglobin
y activeenzyme9
Types to
Classicalcompetitive bindsn'te
panautre
St I bind to active rite mutually exclusive e
I resembles S
structural similarity between 7 a 8 binding site 1
I competes with for active rite
8
S bound enzyme I cannot bind
to
KI
E tS f ES Et P
WT E
WT t
KI
11 I
PI H
WT ki
EI
b Freeenzyme
Effectively b SJ available to enzyme 9km
because appears as if 8 binding lesstightly lb bindingaffinity
If ST SSS IT then I becomes negligible Vmax constant
unchanged
Inhibitors
substance that reduces activity of enzymeby binding to it in
some way
combines with enzyme in way that influences binding of
substrate Ellor turnover number
Inhibitors ND understanding functionality of enzyme
Affect V Max hence affect enzyme activity
May resemble substrate structurally
can compete with sub for active rite
ManyDrugs inhibitors that block action ofspecific enzyme
Reversible vs irreversible
weakbindinginteractions inhibitor remainsboundto enzyme
non covalentinteractions strong covalentinteractions
Hbonds bind to residues AAsidechains
Hydrophobic a prosthetic
groups otherthanA
v d Waals eg Hernegrouponhaemoglobin
y activeenzyme9
Types to
Classicalcompetitive bindsn'te
panautre
St I bind to active rite mutually exclusive e
I resembles S
structural similarity between 7 a 8 binding site 1
I competes with for active rite
8
S bound enzyme I cannot bind
to
KI
E tS f ES Et P
WT E
WT t
KI
11 I
PI H
WT ki
EI
b Freeenzyme
Effectively b SJ available to enzyme 9km
because appears as if 8 binding lesstightly lb bindingaffinity
If ST SSS IT then I becomes negligible Vmax constant
unchanged
