环状细菌素研究进展

细菌素是一类由细菌核糖体合成的抗菌肽，是产生菌获得生存优势的重要手段。与大多数线性细菌素不同，环状细菌素具有N端和C端共价连接的特殊结构。这种环状结构赋予环状细菌素良好的耐热性、广泛的pH适应性和抗蛋白酶降解能力，在食品防腐和对治耐药性细菌领域表现出巨大的应用潜能。通过对已发现的环状细菌素结构分析发现，相对于一级结构，其三级结构的相似性更高，可以作为环状细菌素归类的依据。环状细菌素的生物合成机制尚不清楚，但其环化机制是最具价值的研究热点，可为其他一些肽类物质的合成提供支架，从而提高应用潜能。环状细菌素抑菌机制主要是在目标菌株的细胞膜上穿孔，使胞内物质外流，进而导致目标细菌死亡。其有类似于抗生素的抑菌活性和有别于抗生素的抑菌机制，为治疗日益严重的耐药性病原菌提供了可靠备选资源。本文综述了环状细菌素的构效关系、生物合成和抑菌机制方面的研究进展，希望能够对环状细菌素的深入研究和应用提供有价值的参考。

Research progress of circular bacteriocin

Bacteriocins are a class of ribosomally synthesized antimicrobial peptides produced by bacteria, which endow bacteriocinogenic strains with unique survival advantages. Different from linear bacteriocins, circular bacteriocins have unique N-to-C terminal covalent linkage, and thus they have strong heat tolerance, adaptability to a wide range of pH, as well as certain resistance to protease. Therefore, they show great potential in food antisepsis and antagonization of resistance bacteria. Circular bacteriocins show higher similarity in tertiary structure than in primary structure, laying a basis for the classification. The biosynthesis mechanism of circular bacteriocins is still unclear, whereas the cyclization mechanism is attracting the interest of scholars, given that it can provide scaffolds for the synthesis and the modification of other types of peptide. The antibacterial mechanism of circular bacteriocins is mainly associated with perforation on the cell membrane and the consequential outflow of intracellular substances. With the antibacterial activity similar to or different from antibiotics, they can be potential candidates against the resistance pathogens. In this paper, research on circular bacteriocins was summarized, and the structure-activity relationship, biosynthesis pathway, the mode of action, as well as the application potential of them were highlighted, respectively.