蚯蚓两种抗菌肽的分离纯化及部分性质

Purification and Characterization of Two Antibacterial Peptides From Eisenia fetida

经硫酸铵沉淀、超滤、阳离子交换分离和反相快速蛋白质液相色谱 (FPLC)分析 ,得到了两种新的蚯蚓抗菌肽F 1与F 2 ,经电喷雾离子源质谱 (ESI MS)测定 ,其相对分子质量为 5 35 2 7和 5 19 2 7.串联质谱(MS/MS)数据表明F 1的肽序列为Ac Ala Met Val Ser Ser,F 2的肽序列为Ac Ala Met Val Gly Thr.最小抑菌浓度 (MIC)实验表明 ,F 1与F 2对鹑鸡肠球菌 (Enterococcus gallinarum )、绿脓杆菌 (Pseudomonaspyocyanea)、鲍氏不动杆菌 (Acinetobacterbaumanii)、土生克雷伯氏菌 (Klebsiellaterrigena)的最小抑菌浓度分别为 11 4mg/L和 12 85mg/L ,对粪肠球菌 (Enterococcusfaecalis)的最小抑菌浓度分别为 2 2 8mg/L和2 5 6 8mg/L.对真菌白色念株菌 (Candidaalbicans)

Two novel antibacterial peptides were isolated and characterized from the earthworm Eisenia fetida . The antibacterial peptides were purified to homogeneity by means of cation exchange chromatography and reverse FPLC and named F 1 and F 2. By means of ESI MS, F 1 and F 2 were determined to be two peptides with the relative molecular mass of 535 27 and 519 27. By means of MS/MS, the amino acid sequence of F 1 and F 2 were determined to be Ac Ala Met Val Ser Ser and Ac Ala Met Val Gly Thr respectively. F 1 and F 2 exibited an antibacterial activity not only to bacteria but also to fungi. Minimal inhibitory concentration(MIC) of F 1 and F 2 against several Gram positive and Gram negative bacteria were determined by incubating approximately 10 4～10 5 CFU/ml of cell with serial dilutions of peptide in a 96 well microtiler plate. The MIC of F 1 and F 2 against Enterococcus gallinarum, Pseudomonas pyocyanea, Acinetobacter baumanii, Klebsiella terrigena1 were 11 4 mg/L and 12 85 mg/L. The MIC of F 1 and F 2 against Enterococcus faecalis was 22 8 mg/L and 25 68 mg/L.