| 摘要: |
| 对海洋侧孢短芽孢杆菌(Brevibacillus laterosporus) Lh-1 所产多肽R-1 的性质及作用机理进行了研究。R-1 对温度和pH 稳定, 在pH 11.0～12 条件下, 121 ℃处理1 h, 其活力保持在75%以上。经3 种不同浓度的蛋白酶(碱性蛋白酶、胰蛋白酶、胃蛋白酶)处理4 h 后, 活性保持在80%以上。与常见的金属离子和化学试剂在一起反应, 对抗菌肽R-1 的活性无明显影响, 可以配合一起使用, 仅吐温和SDS对其影响较大。氨基酸分析表明, 抗菌肽R-1 由亮氨酸(Leu)、酪氨酸(Tyr)、缬氨酸(Val)、异亮氨酸(Ile)、赖氨酸(Lys)、甘氨酸(Gly)、蛋氨酸(Met)、丝氨酸(Ser)、丙氨酸(Ala)9 种氨基酸组成, 其中疏水氨基酸居多。抑菌试验表明R-1 的抑菌谱广泛, 对经培养分离出来的大肠杆菌及白假丝酵母菌的扫描电境超微结构观察表明, R-1 的杀菌机制主要是通过含有带正电荷的Lys 与带负电荷的磷脂分子结合, 然后R-1 的疏水端插入到指示菌的疏水区, 改变膜的构象, 从而导致菌体的死亡。 |
| 关键词: 海洋侧孢短芽孢杆菌(Brevibacillus laterosporus) 多肽 性质 作用机理 |
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| 基金项目:国家自然科学基金项目(30571429); 国家“863”计划项目(2006AA10Z349); 青岛市科技计划项目(05-2-JC-81) |
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| Properties and bacteriostatic mechanism of the antimicrobial peptide R-1 |
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| Abstract: |
| We reported the properties and bacteriostatic mechanism of the antimicrobial peptide R-1from marine Brevibacillus laterosporus. R-1 was very stable to keep the antibacterial activity even after incubation at 121 ℃ and in the pH rang of 11.0～12.0 for 1 hours. In addition, R-1 was insensitive to trypsin, chymotrypsin, and alkaline proteinase. R-1 activity was slightly enhanced by Ba2+, Li+, Mg2+, Mn2+, Fe2+, Cu2+, Sr2+, Pb2+, Zn2+, and Ca2+. R-1 showed good compatibility to many common chemical reagents, including EDTA and KH2PO4. Tween and SDS showed obvious effects. Amino acid analysis of R-1 showed that R-1 was composed of Leu, Tyr, Val, Ile, Lys, Gly, Met, Ser, and Ala. R-1 had broad-spectrum against many bacteria including a number of pathogens. Observation by scanning electron microscopy suggested that the bioactivity mechanism of R-1 lied in pertoration of cell membrane, leading to bacterium lysis and death. |
| Key words: Brevibacillus laterosporus, peptide, Properties, Bacteriostatic mechanism |
