New biologically active hybrid bacteriocins constructed by combining regions from various pediocin-like bacteriocins: The C-terminal region is important for determining specificity
New biologically active hybrid bacteriocins constructed by combining regions from various pediocin-like bacteriocins: The C-terminal region is important for determining specificity
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DOI：
10.1128/aem.62.9.3313-3318.1996
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发表时间：
1996-09-01
影响因子：
4.4
通讯作者：
NissenMeyer, J
中科院分区：
文献类型：
--
作者：
Fimland, G;Blingsmo, OR;NissenMeyer, J
由乳酸菌产生的pediocin-like bactericins是具有非常相似初级结构的杀菌多肽，肽合成后进行反相色谱和离子交换色谱，得到了数量和纯度足以表征其结构和作用方式的具有生物活性的pediocin-like bactericins，尽管初级结构相似，但pediocins -like bactericins，即pediocin PA-1、sakacin P、曲曲霉素a和白细胞素a。根据细菌素的一级结构，将这些细菌素的多肽分为两个模块：在相对亲水且保守性较好的n端区域，以及较为多样化且疏水的c端区域，通过多肽合成，将不同的pediocin-like细菌素的相应模块相互交换，构建了4个新的具有生物活性的杂交细菌素，所有的杂交细菌素都具有杀菌活性。不同菌株对杂交菌素的相对敏感性与衍生出c端模块的菌素的相对敏感性相似，而与衍生出n端模块的菌素的相对敏感性有较大差异，因此，类pediocin菌素的c端部分是决定其靶细胞特异性的重要因素。然而，一些合成的细菌素失去了活性，但只有在储存数月后才能检测到。质谱分析表明，这种不稳定性是由于蛋氨酸残基的氧化，导致活性降低了10到100倍。
The pediocin-like bacteriocins, produced by lactic acid bacteria, are bactericidal polypeptides with very similar primary structures, Peptide synthesis followed by reverse-phase and ion-exchange chromatographies yielded biologically active pediocin-like bacteriocins in amounts and with a purity sufficient for characterizing their structure and mode of action, Despite similar primary structures, the pediocin-like bacteriocins, i.e., pediocin PA-1, sakacin P, curvacin A, and leucocin A, differed in their relative toxicities against various bacterial strains, On the basis of the primary structures, the polypeptides of these bacteriocins were divided into two modules: the relatively hydrophilic and well conserved N-terminal region, and the somewhat more diverse and hydrophobic C-terminal region, By peptide synthesis, four new biologically active hybrid bacteriocins were constructed by interchanging corresponding modules from various pediocin-like bacteriocins, All of the new hybrid bacteriocin constructs had bactericidal activity, The relative sensitivity of different bacterial strains to a hybrid bacteriocin was similar to that to the bacteriocin from which the C-terminal module was derived and quite different from that to the bacteriocin from which the N-terminal was derived, Thus, the C-terminal part of the pediocin-like bacteriocins is an important determinant of the target cell specificity, The synthetic bacteriocins were more stable than natural isolates, presumably as a result of the absence of contaminating proteases, However, some of the synthetic bacteriocins lost activity, but this was detectable only after months of storage, Mass spectrometry suggested that this instability was due to oxidation of methionine residues, resulting in a 10- to 100-fold reduction in activity.