Literature
Lysozyme (muramidase) preferentially hydrolyzes the β-1,4-glycosidic bond between N-acetylmuramic acid and N-acetylglucosamine, components of the proteoglycan cell wall of certain microorganisms. This enzyme is found in many organisms. In molecular biology, the enzyme from chicken egg white is commonly used for lysis of E. coli to isolate plasmids (Ref. 1 Mini-Prep: Suppl. 15; pp. 1.6.4-7). The working concentration is 200 μg/300 μl. In the so-called "Maxi-Prep", lysozyme can also be added to increase (approx. 5 - 10%) the plasmid yield (Ref. 1 Maxi-Prep: Suppl. 41; pp. 1.7.2-4). Another application is the lysis of bacteria for the preparation of bacterial RNA (Ref. 1 Suppl. 15; pp. 4.4.4-5). In this case, the working concentration is 40 μg/ml (stock solution 50 mg/ml). Form: The protein itself is lysozyme chloride, the chloride is part of the protein structure. The preparation does not contain free sodium chloride. The maximum chloride content is 4%. Stability: Lyophilized lysozyme powder is stable at +4°C for many years. In solution, stability is several weeks at pH values of 4 - 5 at +4°C and several days at room temperature. The optimum pH is 9.2, the isoelectric point is 11.0. Lysozyme is inhibited by surfactants such as SDS or alcohols and fatty acids, imidazole and indole derivatives. Stock solutions in 10 mM Tris-Cl (pH 8.0) are usually prepared at a concentration of 10, 25 or 50 mg/ml, usually just before use.
