Orientation measurements on membrane systems made from lipopolysaccharides and free lipid A by FT-IR spectroscopy
Tóm tắt
Here we report on investigations into the orientational behaviour of hydrated membrane systems made from lipopolysaccharide and its lipid component, free lipid A, using Fourier-transform infrared spectroscopy and applying attenuated total reflectance. For the investigated lipopolysaccharides — extracted from mutants of Salmonella minnesota and Escherichia coli, and differing in the length of the polysaccharide moiety — the dependence of dichroic ratios on temperature for several vibrations of the hydrophilic and hydrophobic portions was measured, from which the order parameter for the lipid assembly can be calculated. In the lower temperature range (<40°C) for all lipopolysaccharide preparations the evaluation of the dichroic ratios clearly shows the existence of a highly ordered phase, i.e. the gel state of the hydrocarbon chains within lamellar structures. For this phase an order parameter S=0.70±0.05 could be calculated which is lower than that of typical phospholipids in the same phase state (S=0.80±0.05 for e.g. phosphatidylethanolamines). For deep rough mutant lipopolysaccharides at higher temperatures (>40°C) a transition into a disordered, isotropic phase can usually be observed for which an order parameter S=0.25±0.05 could be approximated. The other rough mutant lipopolysaccharides at higher temperatures predominantly form lamellar structures. Only in special cases, under the influence of divalent cations like Mg2+, could isotropic phases also be observed. Free lipid A preparations over the whole temperature range exhibited no unequivocal orientational behaviour. However, the existence of a pure L
β-phase even at lower temperatures may be excluded for these compounds. The observed structural preferences might be of great importance with respect to the expression of biological activities of lipopolysaccharide and free lipid A systems in vivo and in vitro.
Tài liệu tham khảo
Bellamy LJ (1975) The infrared spectra of complex molecules, vol I, 3rd edn. Chapman and Hall, London
Brade H, Galanos C, Lüderitz O (1983) Differential determination of the 3-deoxy-d-mannooctulosonic acid residues in lipopolysaccharides of Salmonella minnesota rough mutants. Eur J Biochem 131:195–200
Brandenburg K, Blume A (1987) Investigations into the thermotropic phase behaviour of natural membranes extracted from Gram-negative bacteria and artificial membrane systems made from lipopolysaccharides and free lipid A. Thermochim Acta 119:127–142
Brandenburg K, Seydel U (1984) Physical aspects of structure and function of membranes made from lipopolysaccharides and free lipid A. Biochim Biophys Acta 775:225–238
Brandenburg K, Seydel U (1985) Thermodynamic investigations on mono- and bilayer systems made from lipid components of Gram-negative bacteria. Thermochim Acta 85:473–476
Brandenburg K, Seydel U (1986) Orientation measurements on ordered multibilayers of phospholipids and sphingolipids from synthetic and natural origin by ATR Fourier transform infrared spectroscopy. Z Naturforsch 41 c:453–467
Casal HL, Mantsch HH (1984) Polymorphic phase behaviour of phospholipid membranes studied by infrared spectroscopy. Biochim Biophys Acta 779:381–401
Coughlin RT, Peterson AA, Haug A, Pownall HJ, McGroarty EJ (1985) A pH titration study on the ionic bridging within lipopolysaccharide aggregates. Biochim Biophys Acta 821: 404–412
Fringeli UP (1977) The structure of lipids and proteins studied by attenuated total reflection (ATR) infrared spectroscopy. Z Naturforsch 32 c:20–45
Fringeli UP, Günthard HsH (1981) Infrared membrane spectroscopy. In: Grell E (ed) Molecular biology biochemistry and biophysics, vol 31: Membrane spectroscopy. Springer, Berlin Heidelberg New York, pp 270–332
Galanos C, Lüderitz O, Westphal O (1969) A new method for the extraction of R lipopolysaccharides. Eur J Biochem 9: 245–249
Gronholz J, Herres W (1985) Understanding FT-IR data processing. Part 3: Further useful computational methods. Intell Instrum Comp 3:45–55
Imoto M, Yoshimura S, Kusomoto S, Shiba T (1984) Total synthesis of lipid A, active principle of bacterial endotoxins. Proc Jpn Acad Ser B 60:285–288
Israelachvili JN, Marcelja S, Horn RG (1980) Physical principles of membrane organization. Qu Rev Biophys 13:121–200
Kirikae T, Inada K, Hirata M, Yoshida M, Galanos C, Lüderitz O (1986) Hemagglutination induced by lipopolysaccharides and lipid A. Microbiol Immunol 30:269–274
Labischinski H, Barnickel G, Bradaczek H, Naumann D, Rietschel ETh, Giesbrecht P (1985) High state of order of isolated bacterial lipopolysaccharide and its possible contribution to the permeation barrier property of the outer membrane. J Bacteriol 162:9–20
Lee DC, Chapman D (1986) Infrared spectroscopic studies of biomembranes and model membranes. Biosci Rep 6:235–256
Mantsch HH, Martin A, Cameron DG (1981) Characterization by infrared spectroscopy of the bilayer to nonbilayer phase transition of phosphatidylethanolamines. Biochemistry 20: 3138–3145
Naumann D, Schultz C, Born J, Labischinski H, Brandenburg K, von Busse G, Brade H, Seydel U (1987) Investigations into the polymorphism of lipid A from lipopolysaccharides of Escherichia coli and Salmonella minnesota. Eur J Biochem 164:159–169
Nikaido H (1986) Architecture of Gram-negative bacterial outer membrane. EOS J Immunol Immunopharmacol 6:53–55
Rietschel ETh, Wollenweber H-W, Brade H, Zähringer U, Lindner B, Seydel U, Bradaczek H, Barnickel G, Labischinski H, Giesbrecht H (1984) Structure and conformation of the lipid A component of lipopolysaccharides. In: Handbook of endotoxin, vol 1: Rietschel ETh (ed) Chemistry of endotoxin. Elsevier, Amsterdam, pp 187–220
Rietschel ETh, Brade H, Brade L, Brandenburg K, Schade U, Seydel U, Zähringer U, Galanos C, Lüderitz O, Westphal O, Labischinski H, Kusumoto S, Shiba T (1987) Lipid A, the endotoxic center of bacterial lipopolysaccharides: Relation of chemical structure to biological activity. In: Watson S (ed) 2nd International Conference on Endotoxins and their detection with the Limulus amebocyte lysate test. Alan R Liss, New York, pp 25–53
Savitzky A, Golay MJE (1964) Smoothing and differentiation of data by simplified least square procedures. Anal Chem 36:1627–1639
Schlecht S, Schmidt G (1969) Möglichkeiten zur Differenzierung von Salmonellen-R-Formen mittels Antibiotica und antibakterieller Farbstoffe. Zbl Bakteriol Mikrobiol Hyg [A] 212:505–511
Seydel U, Brandenburg K (1986) Physical properties of synthetic LPS membranes: Structural polymorphism. EOS J Immunol Immunopharmacol 6:62–65
Vukajlovich SW, Sinoway P, Morrison DC (1986) Activation of human serum complement by bacterial LPS. EOS J Immunol Immunopharmacol 6:73–75