关键词: 丝光绿蝇, 抗菌肽, 聚丙烯酰胺凝胶电泳

Abstract: Objective To induce and preliminarily isolate antibacterial peptide from Lucilia sericata by polyacrylamide gel electrophoresis. Methods After the 3^rd instar larva of L.sericata being induced for 48 h by pricking the hemolymph was collected and tested against Micrococcus lysodeikticus at different doses and different pH conditions. The bacteriostatic effects were observed and the diameters of clear inhibitory ring were recorded respectively. After being bathed at 100 ℃ and 80 ℃ for 30 s, 1 min, 3 min and 5 min respectively, each hemolymph was centrifugated at 10 000 r/min for 10 min to get rid of unwanted proteins, the supernatant was tested against M.lysodeikticus and displayed by polyacrylamide gel electrophoresis. Results The antibacterial ring diameter of induced hemolymph increased along with the increasing of dose, and decreased along with the increasing of pH. The hemolymph didn’t possess antibacterial activity against M.lysodeikticus after being bathed at 100 ℃ for 3 min and 5 min, but possessed antibacterial activity after other treatments. It was also found that the two samples which were bathed at 100 ℃ for 3 min and 5 min were lack of two special bands compared with other treatments. Conclusion It implies that the induced antibacterial substance in the blowfly should possessed stronger antibacterial activity in acid condition. Bathing at 80 ℃ for 1 to 3 min and then centrifuging can get rid of unwanted proteins in a large extent. Maybe the two special bands are the components of the antibacterial peptides induced in the blowfly.