Lysozyme from chicken egg white

Lysozyme from chicken egg white is a glycoside hydrolase with bactericidal and bacteriostatic properties ^[1]. Lysozyme hydrolyzes the β(1-4) glycosidic linkage between N-acetylmuramic acid and N-acetylglucosamine found in the peptidoglycan layer of the bacterial cell wall, causing cell lysis ^[2]. Lysozyme can be used in the cheese-making process to inhibit the growth of spoilage bacteria, preventing various types of cheese from experiencing deterioration in texture, bloating, and off-odors^[3]. Lysozyme is widely used as a cell-disrupting agent for the extraction of bacterial intercellular products and as an antibacterial agent in ophthalmologic preparations ^[4].

Suitable pH: 5.3-6.4. Source: Egg white. Properties: Powder.

Lysozyme is a single peptide chain composed of 129 amino acid residues of 18 types, rich in basic amino acids. Lysozyme contains four disulfide bonds that maintain the enzyme's conformation. Lysozyme is a basic protein with lysine at the N-terminus and leucine at the C-terminus. Lysozyme is a C-type lysozyme and is known to be the most heat-resistant lysozyme.

Definition of Enzyme Activity: a lysozyme activity unit is defined as the 25℃, pH 6.2, under the condition of using gambogic micrococcus suspension at 450nm absorbance change of 0.001 per minute required amount of lysozyme.

Solubility: 0.1M phosphate buffer (pH 6.2), 20mg/ml. Storage conditions: 2-8°C. Purpose: Lysozyme is a kind of alkaline mucopolysaccharide enzyme that hydrolyzes pathogenic bacteria. Lysozyme's primary mechanism involves breaking the β-1,4 glycosidic bonds between N-acetylmuramic acid and N-acetylglucosamine in the bacterial cell wall, thereby decomposing insoluble mucopolysaccharides into soluble glycopeptides, which leads to cell wall rupture, leakage of cellular contents, and bacterial lysis. Lysozyme can directly bind to negatively charged viral proteins, forming complexes with DNA, RNA, and apoproteins, thereby inactivating viruses. Lysozyme is capable of lysing Gram-positive bacteria such as Micrococcus lysodeikticus, Bacillus megaterium, and Sarcina lutea.

References:
[1] Shahmohammadi A. Lysozyme separation from chicken egg white: a review[J]. European Food Research and Technology, 2018, 244(4): 577-593.
[2] Banerjee P, Keener K M, Lukito V D. Influence of carbon dioxide on the activity of chicken egg white lysozyme[J]. Poultry science, 2011, 90(4): 889-895.
[3] Khorshidian N, Khanniri E, Koushki M R, et al. An overview of antimicrobial activity of lysozyme and its functionality in cheese[J]. Frontiers in nutrition, 2022, 9: 833618.
[4] Su C K, Chiang B H. Partitioning and purification of lysozyme from chicken egg white using aqueous two-phase system[J]. Process Biochemistry, 2006, 41(2): 257-263.

Lysozyme from chicken egg white是一种具有杀菌和抑菌特性的糖苷水解酶^[1]。Lysozyme可水解细菌细胞壁肽聚糖层中N-乙酰胞壁酸与N-乙酰葡糖胺之间的β(1-4)糖苷键，导致细胞裂解^[2]。Lysozyme可用于奶酪制作过程，抑制腐败菌的生长，防止各种奶酪出现质地变质、胀气和异味^[3]。Lysozyme被广泛用作提取细菌胞内产物的细胞破碎试剂，以及眼科制剂中的抗菌剂^[4]。

适宜pH：5.3-6.4。来源：鸡蛋清。性状：粉末。

Lysozyme由18种129个氨基酸残基构成的单一肽链，富含碱性氨基酸，有4对二硫键维持酶构型，是一种碱性蛋白质，N端为赖氨酸，C端为亮氨酸。Lysozyme是C型，是已知的最耐热的酶。

活力定义：一个Lysozyme活力单位定义为25℃，pH6. 2条件下，使用藤黄微球菌悬浊液在450nm处每分钟引起吸光度变化为0.001所需溶菌酶的量。

溶解性：0.1M磷酸盐缓冲液（pH 6.2：20mg/ml）。储存条件：2-8℃。用途：Lysozyme是一种能水解致病菌中黏多糖的碱性酶。主要通过破坏细胞壁中的N-乙酰胞壁酸和N-乙酰氨基葡糖之间的β-1,4糖苷键，使细胞壁不溶性黏多糖分解成可溶性糖肽，导致细胞壁破裂内容物逸出而使细菌溶解。Lysozyme还可与带负电荷的病毒蛋白直接结合，与DNA、RNA、脱辅基蛋白形成复盐，使病毒失活。可分解溶壁微球菌、巨大芽孢杆菌、黄色八叠球菌等革兰阳性菌。