Lysozyme - Structure , Sources, and Therapeutic Implications

Introduction

Lysozyme is an important body enzyme that plays a huge role in defense. It is present in most body secretions and was discovered by Sir Alexander Fleming early in the 19th century. It is present in many organisms, including human beings. It has antimicrobial, immunomodulatory, and wound-healing properties. This article aims to explain this enzyme in detail regarding its structure, function, and therapeutic applications. Understanding this topic will help address the challenges and devise solutions and newer formulations to overcome the issues.

What Is the Structure of Lysozyme?

Lysozymes are present in various vertebrates, bacteria, and plants. Three types of lysozymes are known:

• C type (conventional)- Humans possess this type of lysozyme.

• G type (goose type).

• I type (invertebrate type).

The C-type Lysozyme is a small enzyme consisting of 129 amino acid residues. It is a small protein molecule with four disulfide linkages present. It contains two domains connected by an aperture. The domains are named alpha domain and beta domain. The aperture or the cleft is the place of the active conversion or hydrolysis of the inactive form of the enzyme. The lysozyme itself shows a rounded shape. The chemical name is muramidase or muramic acid hydrolase. The hydrolysis of the glycosidic bonds in the molecule is responsible for its activation.

What Are the Sources of This Enzyme?

• Chicken Egg: Chicken eggs are a rich enzyme source, especially the egg white protein. It is also present in eggshell membranes.

• Milk: Mammal’s milk is also a rich source of lysozyme enzymes. The type of milk and other factors vary. Studies have shown higher levels in human, equine, and canine milk. Jenny milk is known for its high content of lysosomal enzyme enzymes and further antimicrobial action.

• Plants: Mung beans, cranberry beans, papaya milky juice, and momordica plants have shown lysosomal secretion.

Secretions of mammals that normally contain lysozyme enzymes include:

• Nasal discharge.

• Saliva.

• Tears - Lysozyme is protective and present in the lacrimal fluid. It also shows its presence in retinal pigment epithelial cells.

• Organ secretions such as placenta and blood.

What Are the Therapeutic Implications of This Enzyme?

1. Antimicrobial: Lysozymes possess the ability to kill microorganisms and bacteria, especially by lysing their cell walls. Studies have proven their remarkable ability to target both Gram-positive and Gram-negative bacteria. They can hydrolyze the bonds of the peptidoglycan layer in the bacterial cell wall. This layer is thinner in Gram-positive bacteria; hence, the lysozymes are more effective comparatively. Hence, they can be utilized as effective antibacterial agents. They have also shown antimicrobial properties against some fungi and viruses.

2. Ophthalmic Solutions: Lysozyme is an enzyme present in tears. Its antimicrobial properties are greatly utilized in eye drops and other contact lens products. They stop the growth of bacteria, thereby decreasing the chances of ophthalmic infections.

3. Immunomodulators: They have a role in affecting many immune cell functions, such as macrophages, dendritic cells, and lymphocytes. They are known to regulate appropriate immune responses when required, thereby helping in host defense.

4. Inflammatory: They affect the pro-inflammatory mediators like cytokines by inhibiting them and their functions. This increases the anti-inflammatory component and can be utilized in various inflammatory conditions of the body.

5. Wound Healing: They play a huge role in wound healing because they can reduce the chances of infection. They reduce the colonization of harmful bacteria at the site of injury and thereby help in faster healing and repair.

6. Oral Care: The enzyme lysozyme in saliva is known for its antibacterial properties in the oral cavity. It is used to develop novel toothpaste and mouthwashes to help prevent gum disease and dental caries to a certain extent.

7. Cosmetics: Many skincare products are incorporated with this enzyme mainly because of its defensive properties. This property is utilized to formulate creams, lotions, and cleansers to prevent bacterial growth in the skin. They have also been used in making toothpaste as they do show a positive effect on inhibiting bacterial growth.

8. Preservatives: They are used in the industry to preserve food and increase shelf life. Their antimicrobial property is the main reason behind this usage. In many countries, they are added to cheese, wine, and dairy products for this reason.

What Are the Future Directions Concerning This Enzyme?

This enzyme has multiple uses, especially because of its excellent antimicrobial activity. It can also be utilized in newer applications, biotechnological advances, and beyond healthcare.

1. Precision Therapy: With the global rise in antibiotic resistance and continued research on finding alternatives, lysozymes are very effective against bacteria by targeting the cell walls. This use can be tailored based on the patient's requirements. The use of appropriate drug delivery systems and aids can make sure the drug reaches its target, thereby reducing any unnecessary effects.

2. Tissue Engineering: Lysozyme can be used in tissue engineering to develop advanced products related to wound healing and research. This requires extensive research and preclinical analysis, and its properties make it an excellent client for this.

3. Recombinant Lysozyme: Lysozyme is produced using recombinant DNA technology. This involves inserting the human lysozyme gene into another organism, like bacteria or yeast, and procuring large batches of the sample enzyme. This enzyme has numerous clinical applications, like an antibiotic, wound repair is accelerated, and is also utilized in formulating multiple drugs and pharmaceutical agents.

4. Biotechnology: Lysozyme enzyme has significant potential in protein purification and bioprocessing. Further research is required to improve the efficiency and cost-effectiveness of using this protein for further biotechnological applications.

Conclusion

Lysozyme is an enzyme used for various applications in the pharmaceutical, healthcare as well as industrial sectors. Their ability to kill bacteria makes them excellent agents for protection from almost all infections. It is used in topical form in many dermatological conditions. Their wound healing and biotechnological applications are also remarkable and are under further research. Further studies in this regard will help formulate new drugs and healthcare products. With a growing concern for antibiotic resistance globally, there is more demand and continued research for alternative antimicrobial agents. Lysozymes are the best available current alternative.