Ríos Colombo Natalia S, Chalón Miriam C, Navarro Silvia A, Bellomio Augusto
Instituto Superior de Investigaciones Biológicas (INSIBIO, CONICET-UNT) and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Chacabuco 461, T4000ILI, San Miguel de Tucumán, Argentina.
Curr Genet. 2018 Apr;64(2):345-351. doi: 10.1007/s00294-017-0757-9. Epub 2017 Oct 5.
This review attempts to analyze the mechanism of action and immunity of class IIa bacteriocins. These peptides are promising alternative food preservatives and they have a great potential application in medical sciences. Class IIa bacteriocins act on the cytoplasmic membrane of Gram-positive cells dissipating the transmembrane electrical potential by forming pores. However, their toxicity and immunity mechanism remains elusive. Here we discuss the role of the mannose phosphotransferase system (man-PTS) as the receptor for class IIa bacteriocins and the influence of the membrane composition on the activity of these antimicrobial peptides. A model that is consistent with experimental results obtained by different researchers involves the non-specific binding of the bacteriocin to the negatively charged membrane of target bacteria. This step would facilitate a specific binding to the receptor protein, altering its functionality and forming an independent pore in which the bacteriocin is inserted in the membrane. An immunity protein could specifically recognize and block the pore. Bacteriocins function in bacterial ecosystems and energetic costs associated with their production are also discussed. Theoretical models based on solid experimental evidence are vital to understand bacteriocins mechanism of action and to promote new technological developments.
本综述试图分析IIa类细菌素的作用机制和免疫性。这些肽是很有前景的新型食品防腐剂，在医学领域也有巨大的潜在应用价值。IIa类细菌素作用于革兰氏阳性菌的细胞质膜，通过形成孔道消散跨膜电势。然而，它们的毒性和免疫机制仍不清楚。在此，我们讨论了甘露糖磷酸转移酶系统（man-PTS）作为IIa类细菌素受体的作用，以及膜组成对这些抗菌肽活性的影响。一个与不同研究者获得的实验结果相符的模型认为，细菌素与靶细菌带负电荷的膜进行非特异性结合。这一步将促进与受体蛋白的特异性结合，改变其功能，并在膜中形成一个独立的孔道，细菌素插入其中。免疫蛋白可以特异性识别并阻断该孔道。还讨论了细菌素在细菌生态系统中的作用以及与其产生相关的能量消耗。基于确凿实验证据的理论模型对于理解细菌素的作用机制和推动新技术发展至关重要。
