富甘氨酸果蝇抗菌肽SK_(66)的抗菌机制研究

Study on the Antibacterial Mechanism of a Glycine-Rich Antibacterial Peptide SK_(66) of Drosophila

为了研究SK66的抗菌机制,对K66-his、AMA-SK66、Trx-SK66进行序列比对和分析,结果发现Trx-SK66是SK66的氮端加了1个Trx蛋白,AMA-SK66是SK66的氮端加了2个丙氨酸和1个甲硫氨酸,SK66-his是在SK66的碳端加了6个组氨酸;比较SK66-his、AMA-SK66和Trx-SK66杀灭细菌活性,结果表明Trx-SK66没有杀菌活性,AMA-SK66杀菌活性大大降低。试验结果说明氮端氨基酸对SK66杀菌活性很重要,尤其氮端氨基酸的极性。

To determine the antibacterial mechanism of SK66,sequence analysis on K66-his,AMA-SK66 and Trx-SK66 were took.The Trx-SK66 was abtained by adding Trx to the N terminal of SK66.Then,by using RP-HPLC,the cleaved product AMA-SK66 was abtained,which its N terminal was added three nonpolar amino acid AMA.SK66-his was obtained by adding 6 His to the C terminal of SK66.By comparison of antibacterial activity of SK66-his,AMA-SK66 and Trx-SK66,results showed that Trx-SK66 has no antibacterial activity and the antibacterial activity of AMA-SK66 decreased largely.It was suggested that N terminal was very vital for bioactivity,especially the polarity of its N terminal amino acid.