乳铁蛋白抗菌机理研究进展

Research Progress on Antibacterial Mechanism of Lactoferrin

乳铁蛋白(Lactoferrin,LF)是发现于哺乳动物初乳中具有多种生物活性的单体糖蛋白,对幼体初期免疫具有重要作用。前人研究发现LF蛋白的酶解后其抗菌活性得到增强,是由于酶解后产生了比其本身抗菌能力更强的肽段。目前关于LF蛋白抗菌活性的报道很多,但其抗菌的具体分子机制尚不清楚。以LF蛋白与细菌细胞膜的结合能力和LF蛋白酶解产物的抗菌活性为切入点,揭示了LF蛋白行使抗菌功能的过程,认为LF蛋白与细菌表面相结合而发生结构变化,进而暴露出敏感的酶切位点,经酶解而释放抗菌活性肽,这些抗菌肽破坏细菌的细胞膜结构,达到抑菌或杀菌的目的。对LF蛋白抗菌机理的阐释将为研制抗菌能力更强的活性蛋白提供理论依据。

Lactoferrin（LF）is a monomer glycoprotein in mammalian colostrum with multi biological activities,thus it plays a vitalrole in initial immunologic reconstitution for young mammals. Previous studies have discovered that enzymatic hydrolysates of lactoferrin haveenhanced antibacterial activity compared to lactoferrin because more active antibacterial peptides were produced by the enzymolysis. At present,molecular mechanism of antibacterial function of lactoferrin is still unclear although many antibacterial activities of lactoferrin were reported. Inthis paper,combination of the bacterial cell membranes and the antibacterial activity of enzymatic hydrolysates were taken as the breakthroughpoint,and the process of LF acting in antibacterial function was explored. It was considered that the mechanism of the antibacterial functionof lactoferrin was that the structure of lactoferrin changed following binding to bacterial surface,then the sensitive restriction enzyme cuttingsites of lactoferrin were exposed,and many antibacterial peptides were released after enzymolysis;subsequently the peptides destroyed themembrane structures of bacterial cells,and thus the purpose of the bacteriostasis or sterilization achieved. In summary,the elucidation ofantibacterial mechanism of lactoferrin provides the theoretical basis for developing active proteins with stronger antibacterial ability.