黑眶蟾蜍皮肤抗菌肽的制备及其性质

收集黑眶蟾蜍皮肤分泌物,经Sephadex G-25去除大分子蛋白后,利用微量测定法进行抗菌活性分析。结果发现:黑眶蟾蜍皮肤分泌物对革兰氏阳性菌——金黄色葡萄球菌、枯草芽孢杆菌的抑制作用较强,对革兰氏阴性菌中的嗜水气单细胞菌也表现出较强的抑制作用,对溶藻弧菌、副溶血弧菌、河流弧菌、大肠杆菌的抑制相对较弱。利用胰蛋白酶对黑眶蟾蜍皮肤抗菌肽水解后,其抗菌活性消失。将黑眶蟾蜍皮肤抗菌肽在37~95℃和pH 2.5~5.0下保温,发现其抗菌活性成分对热及酸耐受性较强。黑眶蟾蜍皮肤分泌物在低浓度无溶血活性。

Preparation and properties of antimicrobial peptides from skin secretion of Bufo melanostictus

The skin secretion of Bufo melanostictus was collected and purified by separate proteins on a Sephadex G-25 column.Antimicrobial activity was determined by miniaturized methods.Antibacterial activities against the Gram positive bacteria Staphylococcus aureus and Bacillus subtilis,and the gram negative bacteria Aeromonas hydrophial were obserbed.Weak antibacterial activity for the gram negative bacteria V.alginolyticus,V.parahaemolyticus,V.fluvialis and Escherichia coli were also observed.The skin secretion of Bufo melanostictus had no antibacterial activity when it was digested with a proteinase trypsin.The result indicated that the antibacterial component was a protein.The peptides cultured at various water temperature and pH showed antimicrobial stability against the temperature and pH.It was no hemolysis for fish red blood cells on the low concentration.