The innate immune systems of several species rely heavily on a class of tiny peptides known as antimicrobial peptides (AMPs). Over 2,600 antimicrobial peptides have been identified so far. Viruses, bacteria, fungi, fish, birds, insects, amphibians, mollusks, and mammals are all common examples.
Antimicrobial Peptide Origins
Peptides Extracted From Microorganisms With Antimicrobial Properties
The two main categories of antimicrobial peptides that originate in microorganisms are those that are bacterial in origin and those that are viral. Bacteriocins are a kind of antimicrobial peptide that originates from bacteria. Protein metabolism in bacteria results in the production of bacteriocins, peptides, or precursor peptide molecules having bactericidal biological activity. These peptides are often long chains of cationic amino acids, making them either hydrophobic or amphiphilic. Bacteriocins are separated into three classes based on their biochemical properties: class I, II, and III. Type I bacteriocins are a subset of antibiotics known as thioethers. They have a molecular weight of less than 5ku and include between 19 and 38 amino acids. These items are resistant to high temperatures and have mucosal action. Lanthionine and -methyllanthione, two uncommon thioether amino acids, are in their makeup.
Antimicrobial Peptides Derived from Plants
Antibacterial peptides isolated from plants effectively against plant infections and human diseases. They serve as an obstacle for the plant’s defensive mechanisms and are hence of interest as antibiotic peptides. Thionin, defensins, lipid transfer proteins, cell-penetrating peptides, ecdysone, etc., are all examples of peptides found in plants with antibacterial properties. They share features such as a positive charge, a disulfide bond, and an outside cell membrane location for their target sites.
Proteolytic enzymes from insects that kill bacteria
More than a million different insect species exist around the globe. They can easily adjust to new environments and use sophisticated defenses. When insects are activated by their surroundings, their hemolymph and other related tissues create antimicrobial peptides. An integral aspect of the insect’s immune system, they are produced naturally as part of its humoral immune system. Its lipid body secretes antibacterial peptides and may prevent the spread of infection in several ways. About 200 different forms of insect antibacterial peptides have been identified so far. Cecropins, lysozyme, defensins, glycine-rich peptides, and proline-rich peptides are the five major classes of these peptides, each with its unique antibacterial action and amino acid sequence.
Antimicrobial Peptides Derived from Amphibians
Amphibians have exposed skin, thrive in extreme humidity, and can breathe via their skin. Because of its physical makeup, it can only exist in a humid environment, which is also ideal for the growth of certain harmful microbes. Amphibians developed a defensive mechanism against harmful germs via constant evolution, allowing them to exploit and adapt to significant habitats and various ecological situations. A crucial effector molecule of innate immunity, antibacterial peptides are secreted by the skin glands of frogs in response to stimulation by adrenaline, stress, trauma, and other conditions and play a crucial part in the amphibian immune defense system. Long-term evolution has resulted in gene duplications and mutations that have led to a vast array of antimicrobial peptide structures and types. Many antimicrobial bioactive compounds are found in amphibian skin secretions, with over 1,400 peptides identified. According to their molecular structure, antimicrobial peptides found in amphibians may be classified as either cyclic antimicrobial peptides with intramolecular disulfide bonds or linear antimicrobial peptides with a -helical structure.
Antimicrobial Peptides from Mammals
Mammal antimicrobial peptides are specific to external bacteria and do not impact the host organism’s healthy cells. Antimicrobial peptides, such as defensins in epithelial tissues and surfactant anionic antimicrobial peptides in the respiratory system, are primarily found in mucosal epithelial cells, neutrophils, and the skin of mammals. Together, phagocytes and their antimicrobial peptides provide the first line of defense in the body.
Two major antimicrobial peptides are found in mammals: defensins and cathelicidins. The most significant group of antimicrobial peptides are the defensins, which have received the most attention from researchers. Two types of defensins are found in mammals, designated as – and -defensins, respectively. Buy peptides only if you are a licensed professional interested in using these compounds for research.
