抗菌肽CEMA的改造与人工合成

MODIFICATION AND SYNTHESIS OF THE CATION ANTIBACTERIAL PEPTIDE CEMA

抗菌肽是一类广泛存在的小分子抗菌多肽物质。从目前所鉴定的抗菌肽来看 ,大多在体外有很强的抑菌作用 ,部分在体内也有很好的抑菌效果。CEMA是一种有抑菌活性的阳离子抗菌多肽 ,但由于对植物细胞的毒害作用 ,其在植物抗病基因工程中的应用受到很大的限制。为了在不降低其强抑菌活性的同时 ,降低对植物细胞的毒害作用 ,对CEMA进行了改造。编码小分子量蛋白的基因的获得 ,大多采用人工合成的方法。合成两条长链部分互补引物 ,经Klenow酶延伸补平是获得目的基因的重要方法之一。该文介绍了一种在此方法基础上的PCR扩增技术 。

Antimicrobial peptides are found in divergent sources. All antimicrobial peptides identified are highly potent antimicrobial agents in vitro and some are effective against a number of phytopathogens in vivo. The application of CEMA, a cation antimicrobial peptide with high antimicrobial activity, is restricted by its toxicity to plant cells. In the present study, CEMA was modified with the purpose of reducing its toxicity to plants cells while maintaining its antimocrobial activity. Chemical synthesis is usually used to obtain target genes encoding peptides with low molecular weight. Klenow polymerase mediated extension of two long complementary oligonucleotides is one of the methods. A PCR method based on Klenow polymerase extension was employed in the study, and the difference between two is discussed in this paper.