Tetraether lipids

Langmuir films have been generated not only from phospholipids but also from tetraether lipids (Fig. 14b). Tetraether glycerophospho- and glycoUpids are typical for ar-chaea, where they may constitute the only polar lipids of the cell envelope [154,155]. Tetraether lipids are membrane-spanning lipids, a single monolayer has almost the same thickness as a phospholipid bilayer. 

FIG. 17 Schematic illustration of the setup for a tip-dip experiment. First glycerol dialkyl nonitol tetraether lipid (GDNT) monolayers are compressed to the desired surface pressure (measured by a Wilhehny plate system). Subsequently a small patch of the monolayer is clamped by a glass micropipette and the S-layer protein is recrystallized. The lower picture shows the S-layer/GDNT membrane on the tip of the glass micropipette in more detail. The basic circuit for measurement of the electric features of the membrane and the current mediated by a hypothetical ion carrier is shown in the upper part of the schematic drawing. 

Planar phospholipid bilayer [137], tetraether lipid monolayer [21]... 

Marine algae as well as aquatic higher plants accumu- phospholipids, methanogens contain diphytanyl late arsenophospholipids.30 tetraether lipids that are both glycerophospholipids... 

Figure 7.29. Structures of some membrane lipids found in the Archaea. These lipids are able to form stable monolayers. (A) A tetraether lipid, diphytanylglycosylglycerol. (B) A tetraether lipid of an extreme thermoacidophile, Sulfolobus sulfataricus. C40H72-so denotes the two biphytanyl chains (including 0 to 3 cyclopentanes). In thermophilic members of the Archaea, the ratio of tetraether lipids to diether lipids rises with increasing temperature. (Figure modified after Hazel and Williams, 1990.)...

Another remarkable feature of the cell membranes of hyperthermophilic archaea is their ability to maintain a liquid-crystalline state over extremely wide ranges of temperature (Horikoshi and Grant, 1998). The exact biophysical basis for this impressive degree of eur-ythermy is not fully understood, albeit the unusual membrane-spanning tetraether lipids could play a role. 

Lipids of the thermophilic deep-sea methanogen, Methanococcus jannaschii [67] are based largely on the macrocyclic diether (cyc-archaeol, 1C) and consist of mono- and di-glucosyl-cyc-archaeol (20A, 23A, respectively. Fig. 6), P-ethanolamine-glucosyl-cyc-archaeol (20B) and cyc-archaeol-PE (15A) a small amount of archaeol-PE (15) is also present. Mco. Jannaschii is also capable of forming caldarchaeol-derived polar lipids [68], and the proportions of diether, macrocyclic diether and tetraether lipids can vary as a function of growth temperature (see section 5.2). 

Hopmans E. C., Schouten S., Pancost R. D., van derMeerM. J. T., and Sinninghe Damste J. S. (2000) Analysis of intact tetraether lipids in archaeal cell material and sediments using high performance liquid chromatography/atmospheric pressure ionization mass spectrometry. Rapid Common. Mass. Spectrom. 14, 585-589. 

Eguchi, T., Ibaragi, K., Kakinuma, K. Total Synthesis of Archaeal 72-Membered Macrocyclic Tetraether Lipids. J. Org. Chem. 1998, 63, 2689-2698. 

Key words AFM, GDNT, Tetraether lipids. Liposome, Sulfolobus acidocaldarius, Archae... 

Bode ML, Buddoo SR, Minnaar SH, du Plessis CA (2008) Extraction, isolation and NMR data of the tetraether lipid calditoglyc-erocaldarchaeol (GDNT) from Sulfolobus... 

Originally assigned a branched chain nonitol struct. Correct struct established by synthesis in 1999. Degradation prod, of a complex of macrocyclic tetraether lipids isol. from membranes of thermo-acidophilic archaebacteria of the Cal-dariella group and Methanospirillum species, e.g. Sulfolobus solfataricus, Also found in Methanobacteria spp. 

In human applications, lipid mixtures for archaeosome preparations have to be well defined and reproducibly produced. It is therefore of importance to be able to obtain pure lipids by controlling both the structure of the lipidic core and that of the polar heads. Total synthesis of archaeal lipid analogues was investigated by several research teams. More convenient synthetic approaches have been developed, of particular interest is the work developed by the Benvegnu team who demonstrated that acyclic tetraethers retained the main structural features of natural archaeal cyclic tetraether lipids (Fig. 31). ... 

Recently, a new and reproducible method to generate stable Upid membranes on SUMs has been described [141]. The membrane-spanning tetraether lipid MPL (main tetraether phospholipid of Thermoplasma acidophilum), and also mixtures of MPL with DPhPC at molar ratios of MPLiDPhPC =1 1 and 5 1, and pure DPhPC are spread at the air-water interface. The monomolec-ular films are subsequently transferred by one raising step (MPL and mixtures) or by a first lowering and subsequent raising step of the electrolyte (DPhPC) onto the SUM. SUM-supported MPL membranes show a lifetime of about 8 h but an additional monomolecular S-layer lattice recrystallized on the lipid-faced side increases the lifetime of the composite membrane significantly to about 21 h [141]. 

Phospholipid bilayers or tetraether lipid films incorporating functional molecules (e.g., ion channels, carriers, pore-forming proteins, proton pumps) represent key elements in the development of biomimetic membranes. Unfortunately, plain lipid membranes are highly susceptible to damage during manual handling proce-... 

Freisleben, H. J. Zwicker, K. Jezek, R John, G. Bettin-Bogutzki, A. Ring, K. Nawroth, T. Reconstimtion of bacteriorhodopsin and ATP synthase from Micrococcus luteus into liposomes of the purified main tetraether lipid from Thermoplasma acidophilum proton conductance and light-driven ATP synthesis. Chem. Phys. Lipids 1995, 78, 137-147. 

Chen, M. and Poulter, C.D. (2010) Characterization of thermophilic archaeal isopentenyl phosphate kinases. Biochemistry, 49, 207-217. Chong, P.L.-G. (2010) Archaebacterial bipolar tetraether lipids physicochemical and membrane properties. Chem. Phys. Lipids, 163, 253-265. Comita, P.B. and Gagosian, R.B. (1983) Membrane lipid from deep-sea hydrothermal vent methanogen a new macrocydic glycerol diether. Science, 222,1329-1331. 

De Rosa, M., De Rosa, S., Gambacorta, A., and Bu Lock, J.D. (1980a) Structure of calditol, a new branched-chain nonitol, and of the derived tetraether lipids in thermoacidophile archaebacteria of the Calderiella group. Phytochemistry, 19, 249-254. 

Hopmans, E.C., Weijers, J.W.H., Schefufi, E., Herfort, L., Sinninghe Damste, J.S., and Schouten, S. (2004) A novel proxy for terrestrial organic matter in sediments based on branched and isoprenoid tetraether lipids. Earth Planet. Sci. Lett., 224, 107-116. 

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