Introduction
Enzymes (E) is a group of biologically active polymers (mainly proteins) that
catalyze almost all metabolic reactions in all living organisms. Enzymes catalyze
virtually every process in the cell. The catalytic activity of certain enzymes is
altered by certain inorganic and organic molecules called modifiers. Those
molecules which increase the enzyme activity are called activators (Positive
modifiers) and those which decrease the enzyme activity are called inhibitors
( Negative modifiers). Compounds which convert the enzymes into inactive
substances and thus adversely affect the rate of enzyme-catalyzed reaction are
called enzyme inhibitors. Such a process is known as enzyme inhibition. Two
broad classes of enzyme inhibitions are generally recognized : Reversible and
Irreversible , depending on whether the enzymeinhibitor complex dissociates
rapidly or very slowly.
Enzymes are very effective biological catalysts that accelerate almost all
metabolic reactions in living organisms. Enzyme inhibitors and activators that
modulate the velocity of enzymatic reactions play an important role in the
regulation of metabolism. Enzyme inhibitors are also useful tool for study of
enzymatic reaction as well as for design of new medicine drugs.
Enzyme inhibitors
Enzymes are different chemical compounds that are combined into a group
because of their only feature—they can suppress enzyme activity. The
suppression of the activity is the result of the binding of inhibitor to the enzyme
molecule that arrests catalytic reaction. Because enzymes catalyze most part of
chemical reactions in living organisms, the enzyme inhibitors play an important
role in the development of different sciences (biochemistry, physiology,
pharmacy, agriculture, ecology) as well as the technologies (production of
pharmaceutical drugs, insecticides, pesticides, chemical weapons, etc.). Many
pharmacological drugs are enzyme inhibitors. The group of well-known
pharmaceutical agents with name nonsteroidal antiinflammatory drugs (NSAIDs)
includes inhibitors of enzyme cyclooxygenase that catalyzes a first step of
synthesis of biologically active compounds prostaglandins that are responsible
for the development of pain, inflammation, fever, contraction of smooth muscle,
formation of blood clots, and others [5]. All inhibitors may be combined in
different groups in accordance with their chemical structure: ions of metals
(Hg+ , Fe2+, Cu+ , Pb2+), organic compounds (e.g., N-ethylmaleimide,
diisopropyl phosphofluoridate, oligomycin), and large bioorganic molecules,
(peptides, proteins, etc). However, this classification does not reflect mechanism
of their interaction with enzyme.
Types Of Inhibition
Types of enzyme inhibition
a) Competitive inhibition
In competitive inhibition, there is only one active binding site (substrate-
binding site) where both substrate and competitive inhibitor
competes to
Enzymes (E) is a group of biologically active polymers (mainly proteins) that
catalyze almost all metabolic reactions in all living organisms. Enzymes catalyze
virtually every process in the cell. The catalytic activity of certain enzymes is
altered by certain inorganic and organic molecules called modifiers. Those
molecules which increase the enzyme activity are called activators (Positive
modifiers) and those which decrease the enzyme activity are called inhibitors
( Negative modifiers). Compounds which convert the enzymes into inactive
substances and thus adversely affect the rate of enzyme-catalyzed reaction are
called enzyme inhibitors. Such a process is known as enzyme inhibition. Two
broad classes of enzyme inhibitions are generally recognized : Reversible and
Irreversible , depending on whether the enzymeinhibitor complex dissociates
rapidly or very slowly.
Enzymes are very effective biological catalysts that accelerate almost all
metabolic reactions in living organisms. Enzyme inhibitors and activators that
modulate the velocity of enzymatic reactions play an important role in the
regulation of metabolism. Enzyme inhibitors are also useful tool for study of
enzymatic reaction as well as for design of new medicine drugs.
Enzyme inhibitors
Enzymes are different chemical compounds that are combined into a group
because of their only feature—they can suppress enzyme activity. The
suppression of the activity is the result of the binding of inhibitor to the enzyme
molecule that arrests catalytic reaction. Because enzymes catalyze most part of
chemical reactions in living organisms, the enzyme inhibitors play an important
role in the development of different sciences (biochemistry, physiology,
pharmacy, agriculture, ecology) as well as the technologies (production of
pharmaceutical drugs, insecticides, pesticides, chemical weapons, etc.). Many
pharmacological drugs are enzyme inhibitors. The group of well-known
pharmaceutical agents with name nonsteroidal antiinflammatory drugs (NSAIDs)
includes inhibitors of enzyme cyclooxygenase that catalyzes a first step of
synthesis of biologically active compounds prostaglandins that are responsible
for the development of pain, inflammation, fever, contraction of smooth muscle,
formation of blood clots, and others [5]. All inhibitors may be combined in
different groups in accordance with their chemical structure: ions of metals
(Hg+ , Fe2+, Cu+ , Pb2+), organic compounds (e.g., N-ethylmaleimide,
diisopropyl phosphofluoridate, oligomycin), and large bioorganic molecules,
(peptides, proteins, etc). However, this classification does not reflect mechanism
of their interaction with enzyme.
Types Of Inhibition
Types of enzyme inhibition
a) Competitive inhibition
In competitive inhibition, there is only one active binding site (substrate-
binding site) where both substrate and competitive inhibitor
competes to
