人工合成抗菌肽的抑菌和溶血作用的分析

为了研究4条人工合成抗菌肽的抑菌和溶血作用。在大肠杆菌悬浮液和绵羊血红细胞悬浮液中,分别加入不同溶度的人工合成抗菌肽,观察其抑菌效果和溶血作用。同时,用圆二色谱仪测定抗菌肽的二级结构。在4条人工合成抗菌肽中,抗菌肽CM-S的抑菌效果为最佳,最小抑菌溶度为25μg/mL,而LB平板菌落的杀菌溶度为50μg/mL;在对绵羊血红细胞的溶血试验中,CM-S在50μg/mL时无溶血作用,100μg/mL时只表现出轻微溶血特性;用圆二色谱仪测定CM-S的二级结构,在2.5%SDS溶液中,208 nm和222 nm出现典型α-螺旋特征峰。人工合成抗菌肽CM-S,含有17个氨基酸,呈典型α-螺旋结构,对大肠杆菌的抑杀效果显著,且溶血性很低,有良好的临床药物开发前景。

Analysis of Antimicrobial Peptide Inhibition Ability on Microbe and Hemolysis on Red Blood Cell

To investigate the inhibition ability of antimicrobial peptides on microbe and hemolysis on animal cell.Four antimicrobial peptides were synthesized by solid-phase methods using N-(9-f1uorenyl)methoxycarbonyl(Fmoc) chemistry and were exposed to Escherichia coli suspension and the sheep red blood cells suspension to investigate their inhibition ability on microbe and hemolysis on animal cell.Far-UV(ultraviolet) circular dichroism spectrum measurement was also used to predict their secondary structures.The results showed that a synthesized peptide,CM-S,was the best one among four peptides,because it not only had the strongest ability in the inhibition of E.coli,but also no significant hemolysis on sheep red blood cells.The minimum inhibitory concentration and the killing bacterial concentration of CM-S was 25μg/mL and 50μg/mL respectively,and CM-S had no hemolysis to the sheep red blood cell at 50μg/mL although a little at 100μg/mL.The peptide secondary structure analysis showed that CM-S possessed a classic alpha helix spectrum,namely,negative bands at 222 nm and 208 nm and a positive band at 193 nm in 2.5% SDS solution.The alpha helix structure implied that the CM-S was more effective for killing microbe,such as E.coli cells in this research.It is possible that CM-S has a value in the medicine exploitation because of its high inhibition on E.coli and low toxicity to animal cell.