Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Gustav Mahlerlaan 3004, NL-1081AL, Amsterdam, The Netherlands.
Biochem Cell Biol. 2012 Jun;90(3):378-88. doi: 10.1139/o11-085. Epub 2012 Feb 24.
Bovine lactoferrin harbors 2 antimicrobial sequences (LFcin and LFampin), situated in close proximity in the N1-domain. To mimic their semi parallel configuration we have synthesized a chimeric peptide (LFchimera) in which these sequences are linked in a head-to-head fashion to the α- and ε-amino group, respectively, of a single lysine. In line with previously described bactericidal effects, this peptide was also a stronger candidacidal agent than the antimicrobial peptides LFcin17-30 and LFampin265-284, or a combination of these 2. Conditions that strongly reduced the candidacidal activities of LFcin17-30 and LFampin265-284, such as high ionic strength and energy depletion, had little influence on the activity of LFchimera. Freeze-fracture electron microscopy showed that LFchimera severely affected the membrane morphology, resulting in disintegration of the membrane bilayer and in an efflux of small and high molecular weight molecules such as ATP and proteins. The differential effects displayed by the chimeric peptide and a mixture of its constituent peptides clearly demonstrate the synergistic effect of linking these peptides in a fashion that allows a similar spatial arrangement as in the parent protein, suggesting that in bovine lactoferrrin the corresponding fragments act in concert in its candidacidal activity.
牛乳铁蛋白含有 2 种抗菌序列（LFcin 和 LFampin），位于 N1 结构域附近。为了模拟它们的半平行结构，我们合成了一种嵌合肽（LFchimera），其中这些序列分别以头对头的方式连接到单个赖氨酸的α-和ε-氨基上。与之前描述的杀菌作用一致，这种肽比抗菌肽 LFcin17-30 和 LFampin265-284 或它们的组合更具有杀真菌活性。强烈降低 LFcin17-30 和 LFampin265-284 杀真菌活性的条件，如高离子强度和能量耗竭，对 LFchimera 的活性几乎没有影响。冷冻断裂电子显微镜显示，LFchimera 严重影响了膜形态，导致膜双层的崩解，并导致小分子和高分子量分子（如 ATP 和蛋白质）的流出。嵌合肽和其组成肽的混合物显示出的差异效应清楚地表明了将这些肽以类似于亲本蛋白的空间排列方式连接的协同效应，表明在牛乳铁蛋白中，相应的片段在其杀真菌活性中协同作用。
