Freeze-fracture planes of methanogen membranes correlate with the content of tetraether lipids

Beveridge, Terrance; Choquet, C. G.; Patel, G. B.; Sprott, G. Dennis

doi:10.1128/jb.175.4.1191-1197.1993

Cited by 47 publications

(21 citation statements)

References 24 publications

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“…In extreme thermophilic and acidophilic archaea (De Rosa et al 1991) membrane spanning (bolaformamphiphilic) ether lipids are found in which the phytanyl chains of two diether lipids are fused to a C40 core. These so-called tetraether lipids form a monolayer in which the lipids span the entire membrane (Choquet et al 1992;Elferink et al 1992;Beveridge et al 1993). In general, ether lipid membranes have a higher stability and a lower permeability than ester-lipid membranes (Elferink et al 1992;Thompson et al 1992).…”

Section: Diversity In Lipid Compositionmentioning

confidence: 97%

Microbial transport: Adaptations to natural environments

Konings

2006

Antonie van Leeuwenhoek

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The cytoplasmic membrane of bacteria is the matrix for metabolic energy transducing processes such as proton motive force generation and solute transport. Passive permeation of protons across the cytoplasmic membrane is a crucial determinant in the proton motive generating capacity of the organisms. Adaptations of the membrane composition are needed to restrict the proton permeation rates especially at higher temperatures. Thermophilic bacteria cannot sufficiently restrict this proton permeation at their growth temperature and have to rely on the much lower permeation of Na + to generate a sodium motive force for driving metabolic energy-dependent membrane processes. Specific transport systems mediate passage across the membrane at physiological rates of all compounds needed for growth and metabolism and of all end products of metabolism. Some of transport systems, the secondary transporters, transduce one form of electrochemical energy into another form. These transporters can play crucial roles in the generation of metabolic energy. This is especially so in anaerobes such as Lactic Acid Bacteria which live under energy-limited conditions. Several transport systems are specifically aimed at the generation of metabolic energy during periods of energy-limitation. In their natural environment bacteria are also often exposed to cytotoxic compounds, including antibiotics. Many bacteria can respond to this live-threatening condition by overexpressing powerful drug-extruding multidrug resistance systems.

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Section: Diversity In Lipid Compositionmentioning

confidence: 97%

Microbial transport: Adaptations to natural environments

Konings

2006

Antonie van Leeuwenhoek

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“…1 The caldarchaeol lipids span the membrane, and liposomes made from these lipids form a monolayer as opposed to the bilayer formed with conventional glycerophospholipids (8,9). The majority of the tetraether lipids are phosphoglycolipids containing one or more sugar residues on one pole, most commonly gulose, glucose, mannose, or galactose, and a phosphopolyol moiety, such as phosphoglycerol, or inositol on the other.…”

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confidence: 99%

Molecular Mechanisms of Water and Solute Transport across Archaebacterial Lipid Membranes

Mathai¹,

Sprott²,

Zeidel³

2001

Journal of Biological Chemistry

144

133

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Archaebacteria thrive in environments characterized by anaeobiosis, saturated salt, and both high and low extremes of temperature and pH. The bulk of their membrane lipids are polar, characterized by the archaeal structural features typified by ether linkage of the glycerol backbone to isoprenoid chains of constant length, often fully saturated, and with sn-2,3 stereochemistry opposite that of glycerolipids of Bacteria and Eukarya. Also unique to these bacteria are macrocyclic archaeol and membrane spanning caldarchaeol lipids that are found in some extreme thermophiles and methanogens. To define the barrier function of archaebacterial membranes and to examine the effects of these unique structural features on permeabilities, we investigated the water, solute (urea and glycerol), proton, and ammonia permeability of liposomes formed by these lipids. Both the macrocyclic archaeol and caldarchaeol lipids reduced the water, ammonia, urea, and glycerol permeability of liposomes significantly (6 -120-fold) compared with diphytanylphosphatidylcholine liposomes. The presence of the ether bond and phytanyl chains did not significantly affect these permeabilities. However, the apparent proton permeability was reduced 3-fold by the presence of an ether bond. The presence of macrocyclic archaeol and caldarchaeol structures further reduced apparent proton permeabilities by 10 -17-fold. These results indicate that the limiting mobility of the midplane hydrocarbon region of the membranes formed by macrocyclic archaeol and caldarchaeol lipids play a significant role in reducing the permeability properties of the lipid membrane. In addition, it appears that substituting ether for ester bonds presents an additional barrier to proton flux.Many archaebacteria thrive in hostile environments, such as hot springs, salt lakes, and acidic or alkaline domains (1, 2). For instance, Methanococcus jannaschii grows optimally at 85°C, pH 6 (3, 4), Thermoplasma acidophilum at 55°C, pH 2.0 (5), and Halobacterium salinarum in near-saturated salt brines (2). The major role of the cell membrane is to provide a selective barrier between the external environment and the inside of the cell. Given the extreme environmental conditions in which these bacteria thrive, it is not surprising that their plasma membranes are composed of lipids that differ markedly in structure and physicochemical properties from the glycerolipids of eubacterial, animal, and plant cell membranes. In these unique bacteria, the membrane lipids are characterized by the presence of ether linkages instead of ester linkages, and they contain regularly branched phytanyl and biphytanyl chains instead of fatty acyl chains (6). The presence of ether rather than ester bonds is thought to contribute to greater chemical stability at extreme pH. Moreover the glycerol ethers contain an sn-2,3 stereochemistry that is opposite that of the naturally occurring sn-1,2 stereochemistry of glycerophospholipids of the other domains (7). The basic lipid core structures of these unique organisms are su...

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“…The biochemical effects of various AMPs on bacterial cell membranes and their properties are well characterized. In contrast to the bacterial membrane lipids consisting of fatty acid esters, archaeal membrane lipids are built from glycerol diethers of isoprenoid alcohols arranged as a bilayer or in several archaea also from glycerol tetraethers that form monolamellar membrane patches (14,22). In addition, the compounds of the archaeal cell wall polymer are structurally highly diverse, ranging from pseudomurein, surface-layer (S-layer) proteins to methanochondroitin (47).…”

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Effects of Antimicrobial Peptides on Methanogenic Archaea

Bang

Schilhabel

Weidenbach

et al. 2012

Antimicrob Agents Chemother

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cAs members of the indigenous human microbiota found on several mucosal tissues, Methanobrevibacter smithii and Methanosphaera stadtmanae are exposed to the effects of antimicrobial peptides (AMPs) secreted by these epithelia. Although antimicrobial and molecular effects of AMPs on bacteria are well described, data for archaea are not available yet. Besides, it is not clear whether AMPs affect them as the archaeal cell envelope differs profoundly in terms of chemical composition and structure from that of bacteria. The effects of different synthetic AMPs on growth of M. smithii, M. stadtmanae, and Methanosarcina mazei were tested using a microtiter plate assay adapted to their anaerobic growth requirements. All three tested methanoarchaea were highly sensitive against derivatives of human cathelicidin, of porcine lysin, and a synthetic antilipopolysaccharide peptide (Lpep); however, sensitivities differed markedly among the methanoarchaeal strains. The potent AMP concentrations affecting growth were below 10 M, whereas growth of Escherichia coli WBB01 was not affected at peptide concentrations up to 10 M under the same anaerobic growth conditions. Atomic force microscopy and transmission electron microscopy revealed that the structural integrity of the methanoarchaeal cells is destroyed within 4 h after incubation with AMPs. The disruption of the cell envelope of M. smithii, M. stadtmanae, and M. mazei within a few minutes of exposure was verified by using LIVE/DEAD staining. Our results strongly suggest that the release of AMPs by eukaryotic epithelial cells is a potent defense mechanism targeting not only bacteria, but also methanoarchaea.

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Freeze-fracture planes of methanogen membranes correlate with the content of tetraether lipids

Cited by 47 publications

References 24 publications

Microbial transport: Adaptations to natural environments

Microbial transport: Adaptations to natural environments

Molecular Mechanisms of Water and Solute Transport across Archaebacterial Lipid Membranes

Effects of Antimicrobial Peptides on Methanogenic Archaea

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