“Antimicrobial Peptides A novel therapeutic agent

1. “ANTIMICROBIAL
PEPTIDES”
A NOVEL THERAPEUTIC
AGENT

2. INTRODUCTION
• Antimicrobial peptides (AMPs) are small molecular weight
proteins with broad spectrum of antimicrobial activity
against bacteria, viruses, and fungi and even transformed
or cancerous cells.
• Antimicrobial peptides (AMPs), also called host defense
peptides (HDPs) are part of the innate immune system that
serve as endogenous antibiotics, found among all classes of
life.
• AMPs are diverse class of naturally occurring molecules that
are produced as a first line of defense by all multicellular
organisms.
• They are potent, broad spectrum class of antibiotics which

3. There are three human AMPs, and they are:
1. Defensins
2. Cathelicidins
3. Histatins
Defensins can be found in:
• Neutrophils
• Paneth cells
• Monocytes
• Macrophages
• Keratinocytes or mucosal cells
• Epithelial cells
Cathelicidins are found in:
• Secretory granules of neutrophils and in NK cells,
• T cells,
• B cells,
• Mast cells and
• Epithelial cells
Histatins very small peptides that are full of histidine and are
found in human saliva.

4. CLASSIFICATION OF
ANTIMICROBIAL PEPTIDE:
AMPs are classified into four different
peptide structures, which are:
• β-sheet
• α-helical
• Loop
• Extended

5. Figure: Different structure of Antimicrobial peptides

6. FUNCTIONS OF AMP:
Functions of antimicrobial peptides include:
• Antimicrobial action — antibacterial (fighting
Gram-positive and Gram-negative bacteria),
antiviral and antifungal action.
• Immunomodulatory effects — the recruitment
of immune cells to sites of infection or injury.
• Wound healing— the formation of new blood
vessels and skin at sites of injury.
• Cell apoptosis — killing pathogens.
• Anticancer activity.
• By destroying harmful microbes, AMPs can
boost immunological activities of animals,
plants and humans.

7. ANTIMICROBIAL ACTIVITY OF
AMP
 AMPs may kill bacteria in two main ways:
1.Disrupting the bacterial plasma membrane:
Fig: Electron micrographs of negatively stained E. coli
untreated (left) and treated (right) with AMP LL-37

8. 2. Disrupting biochemical processes inside the
bacterium:
Figure: Mode of action for intracellular antimicrobial
peptide activity

9. MECHANISM OF ACTION OF AMP
Figure: Mechanism of action of AMPs

10. USES OF AMP AS THERAPEUTIC
AGENTS
Antimicrobial peptides have been used as therapeutic agents; their
use is generally limited to intravenous administration or topical
applications due to their short half-lives. Antimicrobial peptides in
clinical use:
• Bacitracin; for pneumonia, topical use
• Boceprevir; Hepatitis C (oral, cyclic peptide)
• Dalbavancin; bacterial infections
• Daptomycin; bacterial infections
• Enfuvirtide; HIV, subcutaneous injection
• Oritavancin; bacterial infections
• Teicoplanin; bacterial infections
• Telaprevir; Hepatitis C, oral cyclic peptide
• Telavancin; bacterial infection
• Vancomycin; bacterial infection
• Guavanin 2; bacterial infection against Gram-positive and Gram-
negative also.

11. AMP AT A GLANCE:

12. DISCUSSION:
Sequence of an AMP plays an important role in
antimicrobial activity.
Antimicrobial peptides are potential alternatives for
conventional antibiotics because of:
• Ability to kill target cells rapidly
• Broad spectrum of activity
• And modularity
They display multiple modes of action that contain the
following properties,
• Microbicidal
• Bacteriostatic
• Cytolytic

13. CONCLUSION:
New evidence views antimicrobial peptides as
multifunctional molecules that link innate immune
response to adaptive immune system.
AMP production may represent the next major paradigm
for treatment of a broad range of human and animal
diseases.
At present, AMPs are being utilized as models for the
development of novel therapeutic agents that may
ultimately be used as antimicrobials, inflammation
regulators, or for cancer therapies.
The anticancer properties of antimicrobial peptides are
currently not well characterised, but there is speculation

14. REFERENCES:
• https://www.slideshare.net/SayedJamal/antimicrobi
al-peptides-107688935
• https://en.wikipedia.org/wiki/Antimicrobial_peptide
s
• www.dermnetnz.org/topics/antimicrobial-peptides/
• https://www.sciencedirect.com/science/article/pii/S
0960982215014098
• https://www.slideshare.net/ThetSuWin/antimicrobia
l-peptides-seminar-talk-1
• https://www.mdpi.com/2218-273X/8/1/4
• https://www.slideshare.net/BilalNizami/bilal-
mbi11003

15. THANK YOU