Solid state 19F NMR methods for studying biomembranes

Ulrich, Anne S.

doi:10.1016/j.pnmrs.2004.11.001

Cited by 146 publications

(111 citation statements)

References 87 publications

(230 reference statements)

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“…Note that, in practice it is often only possible to obtain the absolute value of a quadrupolar or dipolar splitting (74). Furthermore, from an anisotropic "wave" pattern it is possible to determine the tilt angle and azimuthal rotation of the helix in the membrane (65,75). Since these global angles influence the local orientation of each individual tensor in a specific way, they will have a distinct effect on the amplitude and phase of the wave pattern.…”

Section: Simple Secondary Structuresmentioning

confidence: 99%

“…There are some technical challenges involved in simultaneously using high-power pulses on two similar frequencies, and further improvements are still desirable with regard to probe design. Details about experimental procedures and caveats have been recently reviewed (75). 19 F has a large chemical shift range of several hundred ppm (being Ͼ100 kHz on a 500-MHz spectrometer), so the offset frequency must be set correctly and short pulses are needed to cover the whole spectral range.…”

Section: F Nmr Experimental Considerationsmentioning

confidence: 99%

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NMR methods for studying membrane‐active antimicrobial peptides

Strandberg

Ulrich

2004

Concepts Magnetic Resonance

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142

117

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NMR is a versatile tool for studying interactions between antimicrobial peptides and lipid membranes. Different approaches using both liquid state and solid state NMR are outlined here, with an emphasis on solid state NMR methods, to study the structures of antimicrobial peptides in lipid bilayers as well as the effect of these peptides on model membranes. Different NMR techniques for observing both peptides and lipids are explained, including

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Section: Simple Secondary Structuresmentioning

confidence: 99%

Section: F Nmr Experimental Considerationsmentioning

confidence: 99%

NMR methods for studying membrane‐active antimicrobial peptides

Strandberg

Ulrich

2004

Concepts Magnetic Resonance

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142

117

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“…Compared with other NMR-active nuclei, 19 F has distinct advantages owing to its 1/2 nuclear spin, high gyromagnetic ratio, 100 % natural abundance and low background signal in biological systems. [26] Thus, 13 C and…”

Section: Introductionmentioning

confidence: 96%

Self‐Assembled Amphotericin B Is Probably Surrounded by Ergosterol: Bimolecular Interactions as Evidenced by Solid‐State NMR and CD Spectra

Kasai

Matsumori

Umegawa

et al. 2008

Chemistry A European J

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Amphotericin B (AmB) is thought to exert its pharmacological effects by forming a barrel-stave assembly with ergosterol in fungal membranes. To examine the interaction between AmB and ergosterol (Erg) or cholesterol (Cho), (13)C- and (19)F-labelled covalent conjugates were prepared as reported previously (N. Matsumori et al. Chem. Biol. 2004, 11, 673-679). The CD spectra of the conjugates in a membrane-bound form suggested that the distance between the heptaene moieties of the ergosterol conjugates AmB-C(2)-(6-F)Erg 2 and AmB-C(2)-Erg 3 is similar to that of AmB in ergosterol-containing membranes, but significantly larger than that of AmB in nonsterol or cholesterol-containing membranes. These observations suggest that, as is the case with ergosterol-containing membranes, the conjugated sterol moiety prevents the close contact between the heptaene moieties within the membrane that would reduce channel conductivity of the AmB assemblies. To further investigate this bimolecular interaction, we recorded the solid-state NMR spectra of conjugates 2 and AmB-C(2)-(6-F)Cho 4, which are composed of uniformly (13)C-labelled AmB and 6-fluorinated ergosterol or cholesterol; the conjugates were expected to facilitate the estimation of distances between the fluorine and carbon atoms. By using rotor-synchronous double resonance (rotational echo double resonance of X cluster; RDX) experiments, we deduced the distance between the fluorine atom and its nearest carbon atom in the heptaene moiety of 2 to be less than 8.6 A. This indicates that the B ring of ergosterol comes close to the AmB polyene moiety. A conformational search of the AmB-ergosterol conjugate by using distance constraints derived from the RDX results suggested that ergosterol molecules possibly surround the AmB assembly, which is in contrast with the conventional image in which ergosterol is inserted into AmB molecules.

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“…Later on, some underlying molecular mechanisms for phenotypic variations in bacteria were discovered. Namely, concerted alterations in the expression of one or more genes were shown to cause discrete dichotomous or multiphasic phenotype changes, which are described as phase or antigenic variations (6,12,17,35,(42)(43)(44). These variations are random in the sense that it is impossible to predict which individual cell will undergo the switch, hence they concern the population as a whole.…”

Section: Discussionmentioning

confidence: 99%

“…The primary molecular target of GS is the cellular membrane, though the detailed mechanism of its cytotoxic activity is still a matter of debate (20,29,32,49). Due to its high stability and simple structure, GS is also commonly used as a reference compound in mass spectrometry and nuclear magnetic resonance spectroscopy, and it has served as a model peptide for studying functional mechanisms of membrane-active peptides (9,16,18,30,37,41,42,50). Unfortunately, however, chemically pure GS is no longer available from any open commercial sources (for example, Sigma-Aldrich stopped placing it in their catalogue as of 2000).…”

Section: Gramicidin S (Gs) Is a Cyclic Decapeptide ([Fpvolfpvol] Cyclo )mentioning

confidence: 99%

The Ability ofAneurinibacillus migulanus(Bacillus brevis) To Produce the Antibiotic Gramicidin S Is Correlated with Phenotype Variation

Berditsch

Afonin

Ulrich

2007

Appl Environ Microbiol

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Phenotype instability of bacterial strains can cause significant problems in biotechnological applications, since industrially useful properties may be lost. Here we report such degenerative dissociation for Aneurinibacillus migulanus (formerly known as Bacillus brevis) an established producer of the antimicrobial peptide gramicidin S (GS). Phenotypic variations within and between various strains maintained in different culture collections are demonstrated. The type strain, ATCC 9999, consists of six colony morphology variants, R, RC, RP, RT, SC, and SP, which were isolated and characterized as pure cultures. Correlations between colony morphology, growth, GS production, spore formation, and resistance to their own antimicrobial peptide were established in this study. We found the original R form to be the best producer, followed by RC, RP, and RT, while SC and SP yielded no GS at all. Currently available ATCC 9999 T contains only 2% of the original R producer and is dominated by the newly described phenotypes RC and RP. No original R form is detected in the nominally equivalent strain DSM 2895 T (‫؍‬ATCC 9999 T ), which grows only as SC and SP phenotypes and has thus completely lost its value as a peptide producer. Two other strains from the same collection, DSM 5668 and DSM 5759, contain the unproductive SC variant and the GS-producing RC form, respectively. We describe the growth and maintenance conditions that stabilize certain colony phenotypes and reduce the degree of degenerative dissociation, thus providing a recommendation for how to revert the nonproducing smooth phenotypes to the valuable GS-producing rough ones.

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Solid state 19F NMR methods for studying biomembranes

Cited by 146 publications

References 87 publications

NMR methods for studying membrane‐active antimicrobial peptides

NMR methods for studying membrane‐active antimicrobial peptides

Self‐Assembled Amphotericin B Is Probably Surrounded by Ergosterol: Bimolecular Interactions as Evidenced by Solid‐State NMR and CD Spectra

The Ability ofAneurinibacillus migulanus(Bacillus brevis) To Produce the Antibiotic Gramicidin S Is Correlated with Phenotype Variation

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