改造溶菌酶抑菌活性研究进展

Research Progress on Antibacterial Activity of Modified Lysozyme

溶菌酶是一种天然抗菌剂,能直接水解细菌细胞壁发挥抑菌作用,但溶菌酶仅对革兰氏阳性菌有抑菌活性的特性限制了其在食品和养殖业中的应用。溶菌酶是一种小分子蛋白质,越来越多的研究通过对溶菌酶进行改造和修饰提高了其抑菌活性并扩大了抑菌谱。笔者主要综述了溶菌酶在使用温度、pH、金属离子、化学修饰、与纳米材料结合、与其他溶液复配和利用基因工程技术等条件改造后,抑菌活性均有不同程度的提高,特别是提高了对革兰氏阴性菌的抑制活性。可通过以下几种改造方式提高溶菌酶的抑菌活性:①通过升高温度破坏酶分子内的非共价结合;②通过降低pH影响酶的分子空间结构;③加入金属离子;④对酶分子侧链基团或化学基团进行化学修饰;⑤使用纳米材料负载溶菌酶并固定制成纳米复合材料以破坏细胞壁;⑥利用溶菌酶和其他抑制细菌生长的溶液进行混合制得复合液;⑦使用基因重组技术构建新的溶菌酶表达载体。研究改造溶菌酶对于基础科学的发展及溶菌酶替代抗生素应用于水产和畜禽养殖、开发绿色天然食品防腐剂具有重要指导意义。

Lysozyme is a natural antibacterial agent,which could directly hydrolyze the bacterial cell wall to generate antibacterial activity,however,the property that lysozyme only has antibacterial activity against Gram-positive bacteria limits its application in the field of food and breeding.Lysozyme is a protein with small molecule,more and more studies have modified lysozyme to improve its antibacterial activity and expand its antibacterial spectrum.This paper mainly reviewed that the antibacterial activity of lysozyme had been greatly improved after modification using high temperature,pH,metal ions,chemical modification,combination with nanomaterials or other solutions,and genetic engineering technology,especially for Gram-negative bacteria.The bacteriostatic activity of lysozyme can be improved by the following ways:①Destroying the non-covalent binding within the enzyme molecule by raising the temperature;②Affecting the molecular space structure of the enzyme by reducing pH;③Adding metal ions;④Chemical modification of side chain group or chemical group of enzyme molecule;⑤Lysozyme is loaded on nano materials and fixed into nanocomposites to destroy cell walls;⑥The lysozyme and other solutions inhibiting the growth of bacteria are mixed to obtain a composite solution;⑦Construction of new lysozyme expression vector using gene recombination technology.The research and transformation of lysozyme has important guiding significance for the development of basic science,the application of lysozyme in aquaculture and livestock breeding instead of antibiotics,and the development of green natural food preservatives.