Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2.
J Am Chem Soc. 2012 Dec 5;134(48):19540-3. doi: 10.1021/ja3089229. Epub 2012 Nov 20.
Lantibiotics are ribosomally synthesized antimicrobial peptides produced by bacteria that are increasingly of interest for food preservation and possible therapeutic uses. These peptides are extensively post-translationally modified, and are characterized by lanthionine and methyllanthionine thioether cross-links. Paenibacillus polymyxa NRRL B-30509 was found to produce polymyxins and tridecaptins, in addition to a novel lantibiotic termed paenicidin A. A bacteriocin termed SRCAM 602 previously reported to be produced by this organism and claimed to be responsible for inhibition of Campylobacter jejuni could not be detected either directly or by genomic analysis. The connectivities of the thioether cross-links of paenicidin A were solved using a novel partial desulfurization/reduction strategy in combination with tandem mass spectrometry. This approach overcame the limitations of NMR-based structural characterization that proved mostly unsuccessful for this peptide. Paenicidin A is a highly cyclized lantibiotic, containing six lanthionine and methyllanthionine rings, three of which are interlocking.
类细菌素是由细菌合成的核糖体抗菌肽，越来越受到食品保鲜和可能的治疗用途的关注。这些肽广泛地进行翻译后修饰，并以硫醚交联的链桥氨酸和甲基链桥氨酸为特征。发现多粘类芽孢杆菌 NRRL B-30509 除了产生多粘菌素和十三肽外，还产生一种新型的类细菌素，称为帕尼西林 A。此前曾报道该菌产生一种细菌素 SRCAM 602，据称其可抑制空肠弯曲杆菌，但无论是直接检测还是通过基因组分析，都无法检测到该细菌素。使用一种新的部分脱硫/还原策略结合串联质谱法解决了 paenicidin A 的硫醚交联的连接性问题。这种方法克服了基于 NMR 的结构特征的局限性，对于这种肽，该方法证明大多是不成功的。Paenicidin A 是一种高度环化的类细菌素，含有六个硫桥氨酸和甲基硫桥氨酸环，其中三个是互锁的。
