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Lysozymes are enzymes which inhibit or destroy the growth of bacteria by breaking down the carbohydrate content of their peptidoglycan cell walls. It does this by hydrolyzing the bond between N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM). This causes the bacterial cell to become more easily permeable which can lead to lysis. Therefore lysozyme can be said to be a part of the immune system. It is present in birds, mammals and insects[1]. Lysozymes catalyse reactions by hydrolysis, adding a molecule of water between the two adjacent sugar groups which breaks the single bond[2]. According to Helal R, et al., lysozyme has other properties aside immunity; it acts against viruses, inflammation and cancer.


Uses of lysozyme

Lysozyme is very useful in molecular biology because of its ability to perform cell lysis which is an essential process in the extraction of recombinant DNA[3].

It also protects against infection from viruses as well as prevent yeast or fungal invasion of regions containing mucus[4].


Lysozyme was first discovered to be in chicken eggs in 1909 by Laschtschenko. In 1919 Bloomfield discovered that the enzyme is also present in saliva. Its structure was determined in 1965 by Blake et al. and in 1966, its functional pathway was explained[5].

Molecular Structure

Lysozyme of chicken comprises of one hundred and twenty-eight amino acids. Amino acids of other bird species express a homology and only differ in 4 to 20 amino acids. This enzyme consists of an active site which divides it into two part which are joined by an alpha helix. One part is made up entirely of a beta-sheet structure and the other part is made up of a helix[6][7].


  1. Worthington Biochemical Corporation, (2011). Lysozyme. 1/12/2011.
  2. Bruce Alberts [et al.], Molecular Biology of the Cell, 5th Ed, (2008) p.164
  3. Invitra, (n.d). What is lysozyme?. 1/12/2011.
  4. Invitra, (n.d). What is lysozyme?. 1/12/2011.
  5. Worthington Biochemical Corporation,(2011).Lysozyme. 1/12/2011.
  6. Worthington Biochemical Corporation,(2011). Lysozyme. 1/12/2011.
  7. Helal, R. Bader, D. Melzig, MF. 2012;67(6):564-6. Stimulation of lysozyme release by selected microbial preparations, Pubmed.
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