Pore Bacteriocins

Fig.1. Barrel-stave poration complexes proposed for class 11 bacteriocins. Complexes maybe formed between one or two amphiphilic peptides which oligomerize and form membrane pores and ion channels [21]...

In conclusion, pore formation in the cytoplasmic membrane seems to be a common mode of action of those LAB bacteriocins for which the mode of action has been determined. Some of the class II bacteriocins (lactococcin A, B, G and lactacin F) require a specific receptor molecule for adsorption, whereas nisin also acts on Hposomes and exerts a receptor-independent action. Differences between narrow or wide host-range bacteriocins seem to be correlated with this aspect of a specific receptor, needed for activity. However, which bacteriocin domains confer binding specificities to lipid, protein, or reactive groups remain to be elucidated. 

Chikindas ML, Garcia-Garcera MJ, Driessen AJM, Ledeboer AM, Nissen-Meyer N, Nes IF, Abee T, Konings WN, Venema G (1993) Pediocin PA-1, a bacteriocin from Pediococcus acidilactici PACl.O, forms hydrophyUc pores in the cytoplasmic membrane of target cells. Appl Environ Microbiol 59 3577 - 3584... 

Pore-Forming Toxins (Proteins and Peptides TC l.C.) represent a group of proteins that have considerably expanded over the last few years within the lactic acid bacteria group (Table 4.2). The production of bacteriocins is a very desirable trait with biotechnological applications. Bacteriocins are bacterially produced peptide antibiotics with the ability to kill a limited range of bacteria, usually but not always those that are closely related to the producer bacterium. 

Yoneyama, F., Imura, Y., Ohno, K., et al. (2009). Peptide-lipid huge toroidal pore, a new antimicrobial mechanism mediated by a lactococcal bacteriocin, lacticin Q. Antimicrob Agents Chemother 53, 3211-3217. 

In order to effectively exploit the potential of bacteriocin applications we have to learn more about their mode of action since it becomes increasingly evident that the presumption that bacteriocins act by directly forming pores in the cytoplasmic membrane is not always true. The mechanisms by which these antimicrobial peptides act appear to be nearly as diverse as their structures and physicochemical properties. 

Chikindas, M.L., Garcia-Garcera, M.J., Driessen, A.J., et al. (1993). Rediocin RA-1, a bacteriocin from Rediococcus acidilactici RAC 1.0, forms hydrophiUc pores in the cytoplasmic membrane of target cells. Appl Ertviron Microbiol 59,... 

Moll, G.N., Konings, W.N., and Driessen, A.J. (1999a). Bacteriocins mechanism of membrane insertion and pore formation. Antonie Van Leeuwenhoek 76,185-198. 

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