Lysozyme

Lysozyme biologically is an enzyme that was discovered by Alexander Fleming in the late twentieth. It is produced in the human body and can be discovered in body secretions such as tears, saliva, and milk. It functions as an antimicrobial agent by preventing microbial growth wherever necessary. They are mainly associated with defense against microbial growth, while some ruminants have developed specific categories of lysozyme which act as digestive enzymes also and eventually help in the digestion of food.

What is Lysozyme?

Lysozyme which biologically acts as a defensive agent prevents the growth of bacteria and several other microorganisms by enzymatic cleavage of glycosidic linkage of the bacterial cell wall, which eventually leads to the death of the cell, or by disrupting bacterial membranes, or by activating autolytic enzymes. Lysozyme can be found in a wide range of biological entities including body fluids and tissues of mammals. Lysozyme is a part of the innate immune system of living beings, which is a key defence mechanism.

Lysozymes are widely distributed enzymes that have a specialized hydrolytic activity against bacterial cell wall peptidoglycan. Lysozyme is a protein present in plants, animals, bacteria, and viruses. Examples of Lysozyme-LZ, muramidase, N-acetylmuramoyl hydrolase

Where Is It Found or Where Is It Produced? 

Lysozyme can be discovered in tears, saliva, milk and egg whites. Mucilage linings like the nasal cavity also show the presence of lysozyme. It attempts to destroy bacterias that try to enter our body by nasal passage. Lysozyme is secreted by several specialized cells or glands, including the submucosal gland, neutrophil, macrophages, etc. Lysozyme acts synergically with other polypeptide molecules to carry out its functions. 

Structural Description of Lysozyme

The condensed structure of lysozyme from egg white is made up of a single peptide chain with roughly 129 amino acids present in it. From the terminal -group (N) to the terminal carboxyl group (C), amino acid residues are numbered (C). Every fifth and tenth residue is numbered in the rings.

Functions of Lsozyme

  • Lysozyme functions as an antibacterial agent in several parts of our body, including the nasal chamber, saliva, tears, submucosal glands, etc. 
  • It prevents the entry and growth of infectious microorganisms. 
  • It does so by breaking the chemical bonds of the constituents of the outer wall of bacteria.
  • For instance, a bacterial cell wall is formed of peptidoglycan, which is the specific target site of lysozyme and hence it breaks its structure. Peptidoglycan is formed of an alternate arrangement of N-ACETYLMURAMIC and N-ACETYLGLUCOSAMINE. The bond which exists between N-ACETYLMURAMIC and N-acetylglucosamine is broken by the enzymatic activity of lysozyme, which results in the death of the bacteria and neutralization of the threat posed by the bacteria.

Uses of Lysozyme

  • Our blood delivers bacteria to all regions of the body, it is the most hostile environment for bacteria to grow. In the blood, the lysozymes, coupled with the immune system, protect against infection.
  • Lysozyme defends a variety of surroundings that are potentially bacterial feeding sources.
  • Bacteria are destroyed/killed by lysosomes by the lysis of the bacterial body wall (peptidoglycan) and by activation of enzymes autolytic in nature.
  • It works as an antibacterial agent by cleaving the peptidoglycan component of bacterial cell walls, causing the bacteria to die.
  • A coating of peptidoglycan is found on the surface of the cell wall of bacteria, and the lysozyme attacks this peptidoglycan chain and causes the lysis of the wall. 
  • The backbone of the cell membrane is created by two molecules N-acetylglucosamine and N-acetylmuramic acid, that type of a powerful glycan chain. Lysozymes separate N-acetylglucosamine and N-acetylmuramic acid which leads to Bacterial death
  • Lysozyme is required for the clearance of mucosal inflammation.
  • Lysozyme may have an indirect effect on the Gram-negative bacteria as well. Lysozyme has been utilised successfully in the food business because of its antibacterial qualities. Lysozyme has been used to prevent the rotting of other fresh items, including meat.
  • Ruminants have developed a digestive enzyme called a gastric c type lysozyme, and they profit from the digestion of foregut bacteria after the rumen has fermented most dietary components, including protein.

Conclusion

Lysozyme is biochemically an enzyme, which acts as an antibacterial agent and prevents the growth of bacteria. It can be discovered in tears, saliva, submucosal gland, etc. It also acts synergically with other polypeptide molecules to carry out its functions. It breaks the chemical bonds between the constituents of the bacterial wall, peptidoglycan to kill the cell and hence protect it.