Changes in selected physicochemical properties of lysozyme modified with a new method using microwave field and oxidation

Lysozyme is a type of enzymatic protein found in a wide range of organisms. Among the many applications of lysozyme, the antibacterial activity features caused by the hydrolysis of 1–4 glycosidic bonds between N-acetylmuramic acid and N-acetylglucosamine of gram-positive bacteria are beneficial in the food industry, medicine, trade, and pharmacology. Studies have indicated that specific modifications of lysozyme cause oligomerization of the enzyme, and the resulting dimer, which also undergoes changes in physicochemical properties, shows greater total antibacterial activity. Among these modifications, thermo-chemical methods are one of the most important groups. In this study, the microwave method of the enzyme heating with the associated process of enzyme oxidation was used as a novel thermo-chemical method to induce lysozyme oligomerization. The research shows that using this new method can produce enzymatic preparations composed of approximately 58.9% oligomers, including 33.5% dimer and 25.4% trimer under a hydrogen peroxide concentration of 4% and pH of 8. The maximum percentage of lysozyme dimer of 39.4% was obtained at pH 6.0 with the addition of 2% oxidant. In addition, as a result of the modification process, the hydrolytic activity and surface hydrophobicity of the enzyme were changed.