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Cukkemane A, Baldus M. Characterization of a cyclic nucleotide-activated K(+) channel and its lipid environment by using solid-state NMR spectroscopy. Chembiochem 2013; 14:1789-98. [PMID: 23956185 DOI: 10.1002/cbic.201300182] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Indexed: 01/31/2023]
Abstract
Voltage-gated ion channels are large tetrameric multidomain membrane proteins that play crucial roles in various cellular transduction pathways. Because of their large size and domain-related mobility, structural characterization has proved challenging. We analyzed high-resolution solid-state NMR data on different isotope-labeled protein constructs of a bacterial cyclic nucleotide-activated K(+) channel (MlCNG) in lipid bilayers. We could identify the different subdomains of the 4×355 residue protein, such as the voltage-sensing domain and the cyclic nucleotide binding domain. Comparison to ssNMR data obtained on isotope-labeled cell membranes suggests a tight association of negatively charged lipids to the channel. We detected spectroscopic polymorphism that extends beyond the ligand binding site, and the corresponding protein segments have been associated with mutant channel types in eukaryotic systems. These findings illustrate the potential of ssNMR for structural investigations on large membrane-embedded proteins, even in the presence of local disorder.
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Affiliation(s)
- Abhishek Cukkemane
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 Utrecht (The Netherlands)
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2
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Nickerson KW, Bulla LA. Incorporation of Specific Fatty Acid Precursors During Spore Germination and Outgrowth in Bacillus thuringiensis. Appl Environ Microbiol 2010; 40:166-8. [PMID: 16345590 PMCID: PMC291541 DOI: 10.1128/aem.40.1.166-168.1980] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The selective incorporation of precursors specific for individual fatty acids in germinating and outgrowing spores of Bacillus thuringiensis is described. The specific precursors utilized were [C]butyrate, -isobutyrate, -valerate, and -isovalerate, which were incorporated into even-numbered normal-chain isomers, even-numbered iso-isomers, odd-numbered normal-chain acids, and odd-numbered isohomologs, respectively. This preferential incorporation by B. thuringiensis allows the terminal carbons of specific normal and branched-chain fatty acids, contained within the cytoplasmic membrane, to be labeled with C and, potentially, C.
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Affiliation(s)
- K W Nickerson
- School of Life Sciences, University of Nebraska, Lincoln, Nebraska 68588
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Neyroz P, Franzoni L, Spisni A, Masotti L, Brand L. The chemical synthesis of N-[1-(2-naphthol)]-phosphatidylethanolamine, a fluorescent phospholipid for excited-state proton transfer studies. Chem Phys Lipids 1992; 61:255-63. [PMID: 1326418 DOI: 10.1016/0009-3084(92)90105-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A procedure for the preparation of N-[1-(2-naphthol)]-phosphatidylethanolamine (NAPH-PE) has been developed. The synthesis is based on the Schiff base formation between the NH2 of the phospholipid and the aldehyde moiety of 2-hydroxy-1-naphthaldehyde. Then selective reduction of the imine is used to obtain the stable secondary amine, NAPH-PE. Formation of the intermediate Schiff base and the final product is confirmed by 13C- and 1H-NMR. Similar to free 2-naphthol, the excited-state pKa (pKa*) of its phospholipid derivative appears to be significantly lower than the ground-state pKa. At pH 7.4, the excitation spectrum of NAPH-PE shows no deprotonated species in the ground-state, while the emission spectrum presents a significant contribution of this species. Thus the fluorescent phospholipid exhibits the typical behavior of excited-state proton-transfer probes. NAPH-PE is found to incorporate in dimyristoyllecithin (DML) vesicles. The emission spectrum of the probe inserted in the liposomes is affected by acetate used as a proton acceptor. These properties should also be manifest in other lipid bilayers (e.g., plasma membranes of cells) and used for excited-state proton transfer studies.
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Affiliation(s)
- P Neyroz
- Istituto di Chimica Biologica, Facoltà di Medicina e Chirurgia, Università degli Studi di Parma, Italy
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Ward ES, Ellar DJ, Chilcott CN. Single amino acid changes in the Bacillus thuringiensis var. israelensis delta-endotoxin affect the toxicity and expression of the protein. J Mol Biol 1988; 202:527-35. [PMID: 2845100 DOI: 10.1016/0022-2836(88)90283-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Site-directed mutagenesis has been used to change individual amino acids of the larvicidal 27,000 Mr delta-endotoxin of Bacillus thuringiensis var. israelensis. Basic and acidic residues have been systematically replaced by alanine, and the resulting mutant polypeptides analysed for cytolytic and larvicidal activity, and binding to phosphatidyl choline liposomes. Replacement of residues at positions 154, 163, 164, 213 and 225 results in proteins which accumulate as inclusions in recombinant Bacillus subtilis cells similar to the wild-type, but have considerably reduced in-vitro and in-vivo toxicity. One mutant (Glu45 to Ala45) results in a protein that has reduced activity in vitro, but retains wild-type larvicidal toxicity. In addition, seven other mutations of charged residues result in proteins which form small or no inclusions in recombinant cells, despite being produced at levels similar to the wild-type in six out of seven cases. In most instances, the toxicity of these aberrantly expressed proteins is considerably less than the wild-type, although one (Lys124 to Ala124) results in a polypeptide with approximately threefold increased activity in vitro. A secondary structural model is proposed to explain these observations.
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Affiliation(s)
- E S Ward
- Department of Biochemistry, University of Cambridge, U.K
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Johnston NC, Goldfine H. Isolation and characterization of a novel four-chain ether lipid from Clostridium butyricum: the phosphatidylglycerol acetal of plasmenylethanolamine. BIOCHIMICA ET BIOPHYSICA ACTA 1988; 961:1-12. [PMID: 3382687 DOI: 10.1016/0005-2760(88)90124-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We describe the isolation and characterization of a novel four-chain ether phospholipid in Clostridium butyricum grown on petroselinic acid in the absence of biotin. The results of quantitative analyses of hydrolytic products, selective hydrolysis by mild acid or phospholipase C, 1H-, 13C-, and 31P-NMR, and fast atom bombardment-mass spectroscopy (FABMS) have resulted in the determination of the structure of this lipid as a phosphatidylglycerol acetal of plasmenylethanolamine. Smaller amounts of this lipid have been found in cells grown under similar conditions in the presence of oleic, cis-vaccenic, elaidic or dihydrosterculic acids. It also appears to be present in small amounts in cells grown with biotin. This lipid is structurally related to the more plentiful glycerol acetal of plasmenylethanolamine found in these cells.
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Affiliation(s)
- N C Johnston
- Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia 19104-6076
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6
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Ward ES, Ellar DJ. Bacillus thuringiensis var. israelensis delta-endotoxin. Nucleotide sequence and characterization of the transcripts in Bacillus thuringiensis and Escherichia coli. J Mol Biol 1986; 191:1-11. [PMID: 3025452 DOI: 10.1016/0022-2836(86)90417-1] [Citation(s) in RCA: 73] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The nucleotide sequence of a 1408 base-pair DNA fragment encoding the insecticidal 27,340 Mr delta-endotoxin of Bacillus thuringiensis var. israelensis has been determined by analysis of a recombinant plasmid from Escherichia coli. The hydropathy plot of the protein shows it to be highly hydrophobic, consistent with a postulated cytolytic mechanism of action for the toxin. In addition, the delta-endotoxin transcriptional start points that are used in B. thuringiensis and an E. coli recombinant have been determined. In B. thuringiensis var. israelensis, transcription initiates from a single start point, and gene-specific transcripts are not observed before stage II of sporulation. This is the stage at which delta-endotoxin antigen is first detected, indicating that control of expression is primarily at the transcriptional level for this protein. Analysis of gene-specific transcription in E. coli indicates that at least three start points are utilized in this organism. Interestingly, the highest level of delta-endotoxin mRNA is seen during mid-exponential growth of E. coli and the level appears to decrease as the cells enter the stationary phase of growth.
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van Duijn G, Verkleij AJ, de Kruijff B. Influence of phospholipid peroxidation on the phase behavior of phosphatidylcholine and phosphatidylethanolamine in aqueous dispersions. Biochemistry 1984; 23:4969-77. [PMID: 6498171 DOI: 10.1021/bi00316a022] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The influence of oxygen-induced phospholipid peroxidation on the phase behavior of aqueous dispersions of both egg phosphatidylcholine (egg-PC) and egg phosphatidylethanolamine (egg-PE) has been investigated. Phospholipid peroxidation was followed via malondialdehyde formation and analyses of acyl chain compositions. 13C nuclear magnetic resonance spectroscopy (NMR) and the amino-indicating probe trinitrobenzenesulfonic acid were used to study the effect of peroxidation on the chemical structure of hydrated egg-PE. The macroscopic organization of the phospholipids was monitored by 31P NMR and small-angle X-ray diffraction. Differential scanning calorimetry was employed to study the influence of peroxidation on the thermotropic behavior of egg-PE. The results show that egg-PE is more sensitive to the effects of peroxidation than egg-PC. In the latter, no changes in the macromolecular organization were observed. However, peroxidation strongly influenced the polymorphic phase behavior of PE. Initial peroxidation stabilized hydrated egg-PE in a lamellar system up to 70 degrees C, presumably by modification of the head group. Such modifications were confirmed by 13C NMR experiments, which indicated the formation of Schiff bases between PE head groups and aldehydes. Furthermore, quantitative analyses of trinitrobenzenesulfonic acid reactable egg-PE and the corresponding fatty acid compositions revealed the presence of cross-links between the ethanolamine head groups, likely involving the bifunctional malondialdehyde. Prolonged peroxidation of egg-PE resulted in a loss of order in the system, possibly by the formation of intermediate nonbilayer structures.
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Barrow KD, Collins J, Rogers PL, Smith GM. Lipid composition of an ethanol-tolerant strain of Zymomonas mobilis. ACTA ACUST UNITED AC 1983. [DOI: 10.1016/0005-2760(83)90055-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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9
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Protein-lipid interactions in biological and model membrane systems. Deuterium NMR of Acholeplasma laidlawii B, Escherichia coli, and cytochrome oxidase systems containing specifically deuterated lipids. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)69942-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Yang R, Patel K, Pownall H, Knapp R, Sklar L, Crawford R, Morrisett J. Biophysical properties of a major membrane phospholipid, dielaidoylphosphatidylethanolamine, found in an Escherichia coli fatty acid auxotroph. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(19)86884-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Irving CS, Lapidot A. Effects of binding and bactericidal action of vancomycin on Bacillus licheniformis cell wall organization as probed by 15N nuclear magnetic resonance spectroscopy. Antimicrob Agents Chemother 1978; 14:695-703. [PMID: 727760 PMCID: PMC352536 DOI: 10.1128/aac.14.5.695] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The effects of binding and the bactericidal action of vancomycin on the arrangement and mobilities of cell wall polymers in Bacillus licheniformis were investigated by (15)N nuclear magnetic resonance spectroscopy. The bactericidal action of vancomycin led to reduced mobilities of cell wall teichoic acid and teichuronic acid in surviving cells. The decrease in teichoic acid mobility was also observed upon binding of vancomycin to B. licheniformis cells and resulted from a specific interaction between the antibiotic and teichoic acid, rather than from electrostatic contraction of the cell wall. The reduction in teichuronic acid mobility appeared to be related either to the elastic contraction of the cell wall resulting from loss of cell turgor or to separation of the cell wall from the protoplast membrane. No spectral changes associated with cell wall autolysis or alterations in cell wall composition, amidation, and cross-linking were found in vancomycin-treated B. licheniformis cells. Binding of vancomycin to Micrococcus lysodeikticus cell walls led to a decrease in mobility of C-terminal d-alanine residues but was accompanied by an increase in the mobilities of other peptidoglycan residues. The possible contributions of changes in the arrangements of cell wall polymers to the lethal action of vancomycin is discussed.
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Klein ER, Klein PD. A selected bibliography of biomedical and environmental applications of stable isotopes. II--13C 1971-1976. BIOMEDICAL MASS SPECTROMETRY 1978; 5:321-30. [PMID: 350300 DOI: 10.1002/bms.1200050502] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Irving CS, Lapidot A. The dynamic structure of the Escherichia coli cell envelope as probed by 15N nuclear magnetic resonance spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 470:251-7. [PMID: 334259 DOI: 10.1016/0005-2736(77)90104-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Proton decoupled 15N NMR spectroscopy is shown to be a useful tool for probin the dynamic structure of the bacterial cell envelope. The proton decoupled 15N NMR spectra of Escherichia coli whole cells, cell envelopes and outer membranes were obtained and displayed resonances originating from protein side-chain groups, phosphatidylethanolamine, and peptidoglycan. Removal of phospholipids from the cell envelope resulted in a decrease in the motional freedom of peptidoglycan and cell envelope proteins. The mobility of the protein Arg side-chain groups is increased in the absence of peptidoglycan. These data provide insights into the effect of supramolecular organization on the dynamic structure of the E. coli cell envelope.
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Ingram LO, Chevalier LS, Gabba EJ, Ley KD, Winters K. Propionate-induced synthesis of odd-chain-length fatty acids by Escherichia coli. J Bacteriol 1977; 131:1023-5. [PMID: 330493 PMCID: PMC235565 DOI: 10.1128/jb.131.3.1023-1025.1977] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Exogenous propionate is incorporated in vivo by Escherichia coli as a primer to produce lipids with fatty acids of odd chain lengths. This provides a method for the specific labeling of the three terminal carbons in the fatty acyl chains of phospholipids.
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Ribeiro AA, Dennis EA. 13C nuclear magnetic resonance relaxation studies on the structure of mixed micelles of the nonionic surfactant triton X-100 and phospholipids. J Colloid Interface Sci 1976. [DOI: 10.1016/0021-9797(76)90013-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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