Lactococcal bacteriocins - mode of action and immunity
TL;DR: The lactococcal bacteriocins are hydrophobic cationic peptides, which form pores in the cytoplasmic membrane of sensitive cells.
About: This article is published in Trends in Microbiology.The article was published on 1995-08-01 and is currently open access. It has received 78 citations till now. The article focuses on the topics: Bacteriocin & Antimicrobial peptides.
Summary (2 min read)
Jump to: [Lactococcal bacteriocins: mode of action and immunitv] – [Mode of action of lantlbiotics: nisin] – [REVIEWS] – [Mode of action of non-Iantibiotics Diplococcin] – [Lactostrepcin 5] – [Lactococcins A and B] – [Nisin immunity and resistance] and [Conclusions and perspectives]
Lactococcal bacteriocins: mode of action and immunitv
- It is tempting to assume that different strains of a species produce these substances to enable them to compete for the same ecological niche.
- Class I bacteriocins, or lantibiotics, are small membrane-active peptides that contain the unusual amino acids lanthionine, P-methyllanthionine, dehydroalanine and dehydrobutyrine.
- All the lactococcal bacteriocins that have been thoroughly characterized so far belong to class I or II.
Mode of action of lantlbiotics: nisin
- Nisin is the only lantibiotic produced by L. luctis for which the mode of action has been studied.
- It is active against a broad spectrum of Gram-positive bacteria; Escherichia coli and other Gram-negative bacteria are only affected when their outer membranes are weakened or disrupted by treatment with EDTA or osmotic shock21,22, which makes their inner membrane accessible to the lantibiotic.
REVIEWS
- Nisin has a dual activity against spore-forming bacteria: it inhibits the outgrowth of spores and kills cells in the vegetative state.
- The 2,3_didehydroamino acid residues in nisin are thought to act against spores by interacting with the membrane sulfhydryl groups of germinating spores 23.
- It dissipates the membrane potential of whole cells, cytoplasmic membrane vesicles and artificial membrane vesicles ( liposomes)24125, indicating that the peptide does not require a specific receptor protein for activity or for membrane insertion.
- Membrane disruption is believed to result from the incorporation of nisin into the cytoplasmic membrane to form an ion channel or pore.
- This may account for the differences in sensitivity seen be-tween bacterial species or strains, as permeabilization only occurs in liposomes that contain zwitterionic phospholipids28T2p.
Mode of action of non-Iantibiotics Diplococcin
- The effect of purified diplococcin from L. lactis subsp.
- The addition of 8 arbitrary units of diplococcin to sensitive cells completely abolishes DNA and RNA synthesis within 2 min, which may partially interrupt protein synthesis.
- Small pores allow leakage of protons and other small ions only, whereas amino acids leak through larger pores.
- No receptor is required for nisin activity.
Lactostrepcin 5
- Lactostrepcin 5 (Las.5) and other lactostrepcins have a strong and rapid bactericidal effect on sensitive cells33; only Las5 has been characterized in detail.
- It inhibits uridine uptake and causes leakage of K+ ions and ATP from cells.
- Like diplococcin, Las5 inhibits DNA, RNA and protein synthesis, probably by the inhibition of transport of precursors required for macromolecular synthesis, energy depletion of the cell and/or leakage from the cell of small solutes that are required for various metabolic activities.
- Las5 is equally active against energized and energy-depleted cells33.
Lactococcins A and B
- They belong to a group of small, cationic hydrophobic peptides (including several lantibiotics) that permeabilize membranes28934"6.
- The mode of action of purified lactococcin A has been studied using whole cells of sensitive lactococcal strains and membrane vesicles made from such cells, and also using liposomes obtained from lactococcal phospholipids3'.
- Similar studies on whole cells have also been done using partially purified lactococcin B (Ref. 38) .
- These results indicate that both lactococcins form pores in the cytoplasmic membrane in a voltage-independent manner.
- Low concentrations of lactococcin B allow leakage of protons and ions, whereas ISO-fold more bacteriocin is needed for leakage of glutamate to occur38, which indicates that pores of different sizes can exist.
Nisin immunity and resistance
- There are several mechanisms by which bacteria protect themselves against nisin.
- Nisin resistance (Nis') is not genetically linked to nisin production.
- These results have been united in a model for LciA topology (Fig. 3b ).
- Residues 29-47 are considered to span the cytoplasmic membrane as an amphiphilic a helix by interacting with another transmembrane protein, possibly the lactococcin A receptor.
Conclusions and perspectives
- The past few years have seen significant progress in their understanding of nisin and the lactococcins.
- The structural and immunity genes and the genes encoding the secretion and post-translational modification machinery have been cloned, and the authors are now beginning to understand the modes of action of nisin and the lactococcins A and B, and the way in which the lactococcin A immunity protein LciA works.
- This knowledge, combined with structure-function studies of the bacteriocins, should allow the construction of molecules with enhanced or altered activities and broader specificities for use as, for example, food preservatives.
- A tropism for the mucous membranes of the human respiratory tract; indeed, the upper respiratory tract of humans is virtually the sole reservoir for this organism.
- Infection by H. in/kenzae illustrates the complex interplay that can occur between the host and the pathogen, in a relationship that does not always culminate in disease4.
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TL;DR: Structural, functional, and evolutionary aspects of transmembrane channel-formers are discussed and each type exhibits distinctive features that distinguish them from the other channel protein types and from carriers.
Abstract: Channel-forming proteins/peptides fall into over 100 currently recognized families, most of which are restricted to prokaryotes or eukaryotes, but a few of which are ubiquitous. These proteins fall into three major currently recognized classes: (i) α-helix-type channels present in bacterial, archaeal and eukaryotic cytoplasmic and organellar membranes, (ii) β-barrel-type porins present in the outer membranes of Gram-negative bacterial cells, mitochondria and chloroplasts, and (iii) protein/peptide toxins targeted to the cytoplasmic membranes of cells other than those that synthesize the toxins. High-resolution 3-dimensional structural data are available for representative proteins/peptides of all three of these channel-forming types. Each type exhibits distinctive features that distinguish them from the other channel protein types and from carriers. Structural, functional, and evolutionary aspects of transmembrane channel-formers are discussed.
85 citations
TL;DR: A 1 day turbidometric microplate bioassay was developed for the rapid, accurate and precise quantification of lactic acid bacteria (LAB) bacteriocins (nisin Z and pediocin PA-1) and high precision and accuracy were obtained for all nisin Z concentrations tested.
82 citations
TL;DR: The results suggest that the fragment—by interacting with the target cells and/or pediocin PA-1—interferes specifically with pediOCin-target cell interaction.
Abstract: A 15-mer peptide fragment derived from pediocin PA-1 (from residue 20 to residue 34) specifically inhibited the bactericidal activity of pediocin PA-1. The fragment did not inhibit the pediocin-like bacteriocins sakacin P, leucocin A, and curvacin A to nearly the same extent as it inhibited pediocin PA-1. Enterocin A, however, was also significantly inhibited by this fragment, although not as greatly as pediocin PA-1. This is consistent with the fact that enterocin A contains the longest continuous sequence identical to that of pediocin PA-1 in the region spanned by the fragment. The fragment inhibited pediocin PA-1 to a much greater extent than did the other 29 possible 15-mer fragments that span pediocin PA-1. The results suggest that the fragment—by interacting with the target cells and/or pediocin PA-1—interferes specifically with pediocin-target cell interaction.
78 citations
Cites background from "Lactococcal bacteriocins - mode of ..."
...Bacteriocins produced by gram-positive bacteria are often membrane-permeabilizing cationic peptides with less than 50 amino acid residues (1, 18, 21, 23, 25, 31)....
[...]
TL;DR: The amino acid sequences of the Pln peptides are such that the alpha-helical structures adopted upon interaction with the membrane and each other are amphiphilic in nature, thus enabling membrane interactions.
Abstract: Lactobacillus plantarum C11 produces plantaricin E/F (PlnE/F) and plantaricin J/K (PlnJ/K), two bacteriocins whose activity depends on the complementary action of two peptides (PlnE and PlnF; PlnJ and PlnK). Three of the individual Pln peptides possess some antimicrobial activity, but the highest bacteriocin activity is obtained by combining complementary peptides in about a one-to-one ratio. Circular dichroism was used to study the structure of the Pln peptides under various conditions. All four peptides were unstructured under aqueous conditions but adopted a partly alpha-helical structure in the presence of trifluoroethanol, micelles of dodecylphosphocholine, and negatively charged dioleoylphosphoglycerol (DOPG) liposomes. Far less structure was induced by zwitterionic dioleoylglycerophosphocholine liposomes, indicating that a net negative charge on the phospholipid bilayer is important for a structure-inducing interaction between (positively charged) Pln peptides and a membrane. The structuring of complementary peptides was considerably enhanced when both (PlnE and PlnF or PlnJ and PlnK) were added simultaneously to DOPG liposomes. Such additional structuring was not observed in experiments with trifluoroethanol or dodecylphosphocholine, indicating that the apparent structure-inducing interaction between complementary Pln peptides requires the presence of a phospholipid bilayer. The amino acid sequences of the Pln peptides are such that the alpha-helical structures adopted upon interaction with the membrane and each other are amphiphilic in nature, thus enabling membrane interactions.
73 citations
Cites background from "Lactococcal bacteriocins - mode of ..."
...The bacteriocins produced by gram-positive bacteria are normally membrane-permeabilizing cationic peptides with less than 60 amino acid residues (1, 22, 23, 25, 26, 31)....
[...]
TL;DR: There is an error in the original publication of this paper and the incorrect author name was captured as "Djamel Dridier" instead of "DJamel Drider".
Abstract: There is an error in the original publication of this paper. The incorrect author name was captured as "Djamel Dridier" instead of "Djamel Drider". The original article has been corrected.
69 citations
References
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TL;DR: The biochemical and genetic characteristics of these antimicrobial proteins are reviewed and common elements are discussed between the different classes of bacteriocins produced by these Gram-positive bacteria.
Abstract: Lactic acid bacteria produce a variety of bacteriocins that have recently come under detailed investigation. The biochemical and genetic characteristics of these antimicrobial proteins are reviewed and common elements are discussed between the different classes of bacteriocins produced by these Gram-positive bacteria.
2,013 citations
TL;DR: The range of inhibitory activity by bacteriocins of lactic acid bacteria can be either narrow, inhibiting only those strains that are closely related to the producer organism, or wide, inhibited a diverse group of Gram-positive microorganisms as mentioned in this paper.
1,754 citations
TL;DR: It is demonstrated that nisin is bactericidal to Salmonella species and that the observed inactivation can be demonstrated in other gram-negative bacteria.
Abstract: Nisin, produced by Lactococcus lactis subsp. lactis, has a broad spectrum of activity against gram-positive bacteria and is generally recognized as safe in the United States for use in selected pasteurized cheese spreads to control the outgrowth and toxin production of Clostridium botulinum. This study evaluated the inhibitory activity of nisin in combination with a chelating agent, disodium EDTA, against several Salmonella species and other selected gram-negative bacteria. After a 1-h exposure to 50 micrograms of nisin per ml and 20 mM disodium EDTA at 37 degrees C, a 3.2- to 6.9-log-cycle reduction in population was observed with the species tested. Treatment with disodium EDTA or nisin alone produced no significant inhibition (less than 1-log-cycle reduction) of the Salmonella and other gram-negative species tested. These results demonstrated that nisin is bactericidal to Salmonella species and that the observed inactivation can be demonstrated in other gram-negative bacteria. Applications involving the simultaneous treatment with nisin and chelating agents that alter the outer membrane may be of value in controlling food-borne salmonellae and other gram-negative bacteria.
586 citations
TL;DR: Transcription analyses of several L. lactis strains indicated that an expression product of the nisA gene, together with NisR, is required for the activation of nisinA transcription, indicating that NisI plays a role in the immunity mechanism.
Abstract: The nisin gene cluster nisABTCIPR of Lactococcus lactis, located on a 10-kbp DNA fragment of the nisin-sucrose transposon Tn5276, was characterized. This fragment was previously shown to direct nisin-A biosynthesis and to contain the nisP and nisR genes, encoding a nisin leader peptidase and a positive regulator, respectively [van der Meer, J. R., Polman, J., Beerthuyzen, M. M., Siezen, R. J., Kuipers, O. P. & de Vos, W. M. (1993) J. Bacteriol. 175, 2578–2588]. Further sequence analysis revealed the presence of four open-reading frames, nisB, nisT, nisC and nisI, downstream of the structural gene nisA. The nisT, nisC and nisI genes were subcloned and expressed individually in Escherichia coli, using the T7-RNA-polymerase system. This resulted in the production of radio-labelled proteins with sizes of 45 kDa (NisC) and 32 kDa (NisI). The nisT gene product was not detected, possibly because of protein instability. The deduced amino acid sequence of NisI contained a consensus Iipoprotein signal sequence, suggesting that this protein is a lipid-modified extracellular membrane-anchored protein. Expression of nisI in L. Iactis provided the cells with a significant level of protection against exogeneously added nisin, indicating that NisI plays a role in the immunity mechanism. In EDTA-treated E. coli cells, expression of nisI conferred up to a 170-fold increase in immunity against nisin A compared to controls. Moreover, a lactococcal strain deficient in nisin-A production, designated NZ9800, was created by gene replacement of nisA by a truncated nisA gene and was 10-fold less resistant to nisin A than the wild-type strain. A wild-type immunity level to nisin and production of nisin was obtained in strain NZ9800 harboring complementing nisA and nisZ plasmids. Transcription analyses of several L. IIactis strains indicated that an expression product of the nisA gene, together with NisR, is required for the activation of nisA transcription.
564 citations
TL;DR: The data suggest that the cytoplasmic membrane is the primary target and that membrane disruption accounts for the bactericidal action of nisin.
Abstract: The peptide antibiotic nisin was shown to cause a rapid efflux of amino acids and Rb+ from the cytoplasm of gram-positive bacteria (Staphylococcus cohnii 22, Bacillus subtilis W 23, Micrococcus luteus ATCC 4698, and Streptococcus zymogenes 24). It strongly decreased the membrane potential of cells as judged by the distribution of the lipophilic tetraphenylphosphonium cation. Ascorbate-phenazine methosulfate-driven transport of L-proline by cytoplasmic membrane vesicles was blocked after addition of nisin, and accumulated amino acids were released from the vesicles. Soybean phospholipid (asolectin) vesicles were not affected by nisin. The data suggest that the cytoplasmic membrane is the primary target and that membrane disruption accounts for the bactericidal action of nisin.
379 citations