Conti Stefania, Radicioni Giorgia, Ciociola Tecla, Longhi Renato, Polonelli Luciano, Gatti Rita, Cabras Tiziana, Messana Irene, Castagnola Massimo, Vitali Alberto
Dipartimento di Scienze Biomediche, University of Parma, Parma, Italy.
Biochim Biophys Acta. 2013 Mar;1828(3):1066-74. doi: 10.1016/j.bbamem.2012.12.013. Epub 2012 Dec 26.
A proline-rich peptide of 2733Da, isolated from pig parotid granule preparations was tested against different pathogenic fungi. It showed interesting antifungal activity towards a clinical isolate of Cryptococcus neoformans, with an EC(50) of 2.2μM. Neither cytotoxic nor haemolytic effects were observed towards mammalian cells. Circular dichroism and infrared spectroscopic studies showed that the peptide adopted a combination of polyproline type-II, β-turn and unordered conformations at physiological temperatures. Temperature dependent experiments evidenced a tendency to adopt a polyproline-II helix conformation. From experiments with lipid vesicles, Neutral Red Uptake (NRU), haemolytic assays, and confocal microscopy studies, it could be hypothesized that the peptide may exert its antifungal effect by interacting with an intracellular target rather than through membrane damage.
从猪腮腺颗粒制剂中分离出的一种分子量为2733Da的富含脯氨酸的肽，针对不同的致病真菌进行了测试。它对新型隐球菌的临床分离株显示出有趣的抗真菌活性，半数有效浓度（EC50）为2.2μM。未观察到对哺乳动物细胞的细胞毒性和溶血作用。圆二色性和红外光谱研究表明，该肽在生理温度下采用了聚脯氨酸II型、β-转角和无序构象的组合。温度依赖性实验证明了其倾向于采用聚脯氨酸II型螺旋构象。通过脂质囊泡实验、中性红摄取（NRU）、溶血试验和共聚焦显微镜研究，可以推测该肽可能通过与细胞内靶点相互作用而非通过膜损伤来发挥其抗真菌作用。
