Biochemistry

1. MOTHER PATERN COLLEGE
OF HEALTH SCIENCES
BIOCHEMISTRY 310
Topic: Enzyme Inhibition
Group # 1: Members;
Giftee J. Roumi
Stephanie S. Stevens
James B. Kowah
Amram W.G Cooper
Mariama Bah
Michelle Gwaikolo
Jesse Kodah
Submitted to: Mr. Alvin Grugbaye Date: April 22, 2022

2. Objectives of this work
By the end of this presentation, students will be able to:
 Define and discuss Enzyme Inhibition
 Compare and contract the different types of inhibitors,
with examples.
 Evaluate the difference between a competitive
versus non-competitive drug inhibitor

3. Enzyme Inhibitors
Enzyme Inhibitors are small molecules and ions capable of
binding to enzymes in order to reduce their catalytic activity.
Enzyme Inhibitors are important controlling machanism in
biological systems as it is the process used by many drugs in
the effective reduction of diseasemediated enzyamtic activity.
Enzyme Inhibitors
Irreversible enzyme inhibitors Reversible enzyme inhibitors

4. What is Irreversible enzyme inhibitors?
Irreversible inhibitors bind tightly to the enzymes, thus
dissociating very slowly from it.
They can form either covalent or non-covalent bonds with their
target.
Mant important drugs are irrevesible enzyme inhibitors.
Eg: Penicillin, an antibiotic capable of killing bacteria by
covalently binding to the enzyme transpeptidase, therefore
preventing the synthesis of the bacterial cell wall.

5. Classification of Irreversible enzyme inhibitors
Irreversible inhibitors can be classified into three categories: group-
specific reagents, substrate analogs and suicide inhibitors.
Group-specific reagents can be bind to a particular amino-acid
residue of the enzymes and irreversibly modify it.
Substrate analogs present a similar structure to the substrate of
the enzyme and can covalently modify its active site residue.
Suicide inhibitors are the most specific enzyme inhibitors. They
bind as a substrate to the enzyme.

6. What is Reversible enzyme inhibitors?
Reversible inhibitors are inactivates enzymes, which can
dissociate from the enzymes
Reversible inhibitors form non-covalent bonds with the
enzyme.
They are characterized by a rapid dissociation from their target.

7. Classification of Reversible enzyme inhibitors
Reversible inhibitors can be classified into two main categories:
competitive and non-competitive inhibitors.
 Competitive inhibition are substrate analog that bind to
substrate binding site of enzyme. Eg; Malonate is a competitive
inhibitor for succinate dehydrogenase.
 Non-competitive inhibition is where the inhibitor reduces the
activity of the enzyme and binds eqqually well to the enyme
whether or not it has already bound the substrate. Eg: Cynide
combines with the iron in the enzymes cytochrome oxidase.

8. Differences and similarities between Irreversible and
Reversible enzyme inhibitors
Irreversible inhibitors bind tightly to the target enzyme and the dissociation odfenzyme-
inhibitor complex is very slow, which reversible inhibitors inhibitors are characterized with
rapid dissociation of the enzyme- inhibitor complex.
Irreversible inhibitors have three categories: group-specific reagents, substrate analogs and
suicide. While, reversible inhibitors have two categories; competitve and non-competitive.
Irreversible substrate analogs and reversible competitive inhibitors act similarly by
imitating the enzyme specific substrate.
Substrate analogs irreversibly modify the active site of the enzyme, while the competitive
onhibition can be reversed by increasing substrate concentration.
Irreversible enzyme inhibitors and reversible enzyme inhibitors are capable of binding to
enzymes and reducing their catalytic activity

9. Difference between a competitive versus non-
competitive drug inhibitors