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

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.