Lai Yu-Ping, Peng Yi-Fei, Zuo Yi, Li Jun, Huang Jing, Wang Lin-Fa, Wu Zi-Rong
Laboratory of Molecular Biology, School of Life Sciences, East China Normal University, Shanghai, China.
Biochem Biophys Res Commun. 2005 Mar 4;328(1):243-50. doi: 10.1016/j.bbrc.2004.12.143.
Antimicrobial peptides from human skin are an important component of the innate immune response and play a key role as a first line of defense against infections. One such peptide is the recently discovered dermcidin-1L. To better understand its mechanism and to further investigate its antimicrobial spectrum, recombinant dermcidin-1L was expressed in Escherichia coli as a fusion protein and purified by affinity chromatography. The fusion protein was cleaved by factor Xa protease to produce recombinant dermcidin-1L. Antimicrobial and hemolytic assays demonstrated that dermcidin-1L displayed microbicidal activity against several opportunistic nosocomial pathogens, but no hemolytic activity against human erythrocytes even at concentrations up to 100 microM. Structural studies performed by circular dichroism spectroscopy indicated that the secondary structure of dermcidin-1L was very flexible, and both alpha-helix and beta-sheet structures might be required for the antimicrobial activity. Our results confirmed previous findings indicating that dermcidin-1L could have promising therapeutic potentials and shed new light on the structure-function relationship of dermcidin-1L.
人皮肤中的抗菌肽是先天性免疫反应的重要组成部分，作为抵御感染的第一道防线发挥着关键作用。其中一种这样的肽是最近发现的皮肤杀菌素-1L。为了更好地理解其作用机制并进一步研究其抗菌谱，重组皮肤杀菌素-1L在大肠杆菌中作为融合蛋白表达，并通过亲和色谱法纯化。融合蛋白经因子Xa蛋白酶切割以产生重组皮肤杀菌素-1L。抗菌和溶血试验表明，皮肤杀菌素-1L对几种机会性医院病原体具有杀菌活性，但即使在浓度高达100微摩尔时对人红细胞也没有溶血活性。通过圆二色光谱进行的结构研究表明，皮肤杀菌素-1L的二级结构非常灵活，抗菌活性可能需要α-螺旋和β-折叠结构。我们的结果证实了先前的发现，表明皮肤杀菌素-1L可能具有有前景的治疗潜力，并为皮肤杀菌素-1L的结构-功能关系提供了新的线索。
