X-Ray Diffraction on Biomembranes with Emphasis on Lipid Moiety

Laggner, Peter

doi:10.1007/978-1-4615-1863-1_11

Cited by 14 publications

(8 citation statements)

References 129 publications

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“…4) which vanished around 42°C. The broad reflections observed in the small-angle X-ray diffraction patterns (data not shown), indicative of a single bilayer transform (Glatter, 1991 ;Laggner, 1994), confirm the unilamel-lar nature of these liposomes in agreement with electron micrographs . Only minor changes were observed with respect to temperature and sample compo$tion.…”

Section: Concentration Effects Of Pgla On the Phase Behavior Ofsupporting

confidence: 75%

Structural Aspects of the Interaction of peptidyl‐glycylleucine‐carboxyamide, a Highly Potent Antimicrobial Peptide from Frog Skin, with Lipids

Latal

Degovics

Epand

et al. 1997

European Journal of Biochemistry

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The interaction of PGLa (peptidyl-glycylleucine-carboxyamide), a 21 -amino-acid residue cationic peptide, isolated from the skin of the South African clawed frog, Xenopus luevis, with model membrane systems was investigated. Our studies focussed on the importance of the difference in the phospholipid composition of bacterial and erythrocyte membranes. This is of particular interest to gain information on the specificity of membranolysis exhibited by this peptide against bacteria but not against erythrocytes.In phosphate buffer at physiological pH, as well as in the presence of the zwitterionic phosphatidylcholine and sphingomyelin, the peptide had a random structure but it adopted an a-helical conformation in the presence of negatively charged lipids. Furthermore, calorimetric experiments showed that PGLa had no effects on the thermotropic phase behavior of liposomes composed of the choline phosphatides, while separation of a distinct peptide-rich domain was observed for phosphatidylglycerol liposomes. In addition to the main transition of pure 1,2-dipalmitoylglycerophosphoglycerol at 40°C a second transition owing to the peptide-perturbed lipid domains was found at 41 "C. This conclusion is supported by X-ray diffraction experiments which indicated that PGLa penetrates into the hydrophobic core of the bilayer inducing an untilting of the hydrocarbon chains as observed in the gel phase of the pure lipid. These results demonstrate that this antibacterial peptide specifically interacts with negatively charged lipid membranes, which are characteristic of bacterial membranes. This can be explained based on the structural features of PGLa.

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Section: Concentration Effects Of Pgla On the Phase Behavior Ofsupporting

confidence: 75%

Structural Aspects of the Interaction of peptidyl‐glycylleucine‐carboxyamide, a Highly Potent Antimicrobial Peptide from Frog Skin, with Lipids

Latal

Degovics

Epand

et al. 1997

European Journal of Biochemistry

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“…Thus, competition between Se and Cd for the specific binding sites in envelope membrane proteins may be considered as another mechanism of Se's protective action, as we previously suggested (Filek et al, 2009). In the present experiment, the SAXS method was used as a very sensitive technique for membrane structure determination (Laggner, 1994(Laggner, , 1999Rappolt et al, 2008). The results point to differences in the chloroplast structure of rape seedlings cultured in the presence of both Cd and Cd+Se in comparison to that cultured on control media.…”

Section: Discussionmentioning

confidence: 98%

Effect of selenium on characteristics of rape chloroplasts modified by cadmium

Filek

Gzyl-Malcher

Zembala

et al. 2010

Journal of Plant Physiology

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“…The intact chloroplast structure was determined from SAXS measurements carried out on a SWAXcamera (HECUS X-ray Systems, Graz, Austria) as described previously (Laggner and Mio, 1992;Laggner, 1994;Filek et al, 2005). Ni-filtered Cu-Ka-radiation (l ¼ 1:54Å) originating from a rotating Cu-anode X-ray generator, (Rigaku, Japan) operating at 50 kV and 60 mA was used.…”

Section: Small-angle X-ray Scattering (Saxs) Experimentsmentioning

confidence: 99%