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PubMed2000

Monoclonal antibody detection of naphthalene dioxygenase from Pseudomonas aeruginosa 2NR.

A monoclonal antibody, designated mAb alpha(CT), was generated against a peptide of the ISP(NAP) alpha-subunit of the naphthalene dioxygenase (NDO) enzyme of Pseudomonas aeruginosa. Since NDO expression is induced by aromatic hydrocarbons, its detection is important as a tool for environmental biomonitoring. This antibody is highly specific and works well both in an indirect ELISA assay and Western Blot analysis, allowing the detection of Pseudomonas spp. expressing the NDO inducible enzyme. The detection threshold for the ELISA assay developed in this work was 10(4) colony forming units (cfu) per ml. Thus, this mAb could represent a powerful tool to test for pollutants in soil, groundwater, and other natural environments.

Amino Acid Sequence↗
PubMed1980

Ipodate and 8-anilino-1-naphthalene sulfonic acid block receptor binding of T3 in rat liver.

We have determined that 8-anilino-1-naphthalene sulfonic acid (ANS) and ipodate are effective inhibitor in vitro of 125I-T3 binding to rat hepatic nuclei receptors. Both of these agents are estimated to have a Kd for the T3 receptor of about 1--2 x 10(-4) M. Indirect preliminary studies suggest that ANS is a non-competitive inhibitor and ipodate is a competitive inhibitor of T3 binding. Compounds such as tyropanoate and diatrizoate and iodide had no effect on T3 receptor binding. Further in vivo studies with ipodate suggested that T3 receptor binding inhibition also occurred when ipodate was given intravenously to rats.

Anilino Naphthalenesulfonates↗
PubMed2004

Core excitations of naphthalene: vibrational structure versus chemical shifts.

High-resolution x-ray photoelectron emission (XPS) and near-edge x-ray absorption fine structure (NEXAFS) spectra of naphthalene are analyzed in terms of the initial state chemical shifts and the vibrational fine structure of the excitations. Carbon atoms located at peripheral sites experience only a small chemical shift and exhibit rather similar charge-vibrational coupling, while the atoms in the bridging positions differ substantially. In the XPS spectra, C-H stretching modes provide important contributions to the overall shape of the spectrum. In contrast, the NEXAFS spectrum contains only vibrational progressions from particular C-C stretching modes. The accuracy of ab initio calculations of absolute electronic transition energies is discussed in the context of minute chemical shifts, the vibrational fine structure, and the state multiplicity.

Journal Article↗
PubMed2000

Structural basis for the interaction of the fluorescence probe 8-anilino-1-naphthalene sulfonate (ANS) with the antibiotic target MurA.

The extrinsic fluorescence dye 8-anilino-1-naphthalene sulfonate (ANS) is widely used for probing conformational changes in proteins, yet no detailed structure of ANS bound to any protein has been reported so far. ANS has been successfully used to monitor the induced-fit mechanism of MurA [UDPGlcNAc enolpyruvyltransferase (EC )], an essential enzyme for bacterial cell wall biosynthesis. We have solved the crystal structure of the ANS small middle dotMurA complex at 1.7-A resolution. ANS binds at an originally solvent-exposed region near Pro-112 and induces a major restructuring of the loop Pro-112-Pro-121, such that a specific binding site emerges. The fluorescence probe is sandwiched between the strictly conserved residues Arg-91, Pro-112, and Gly-113. Substrate binding to MurA is accompanied by large movements especially of the loop and Arg-91, which explains why ANS is an excellent sensor of conformational changes during catalysis of this pharmaceutically important enzyme.

Alkyl and Aryl Transferases↗
PubMed1996

Unexpected binding mode of the sulfonamide fluorophore 5-dimethylamino-1-naphthalene sulfonamide to human carbonic anhydrase II. Implications for the development of a zinc biosensor.

The three-dimensional structure of human carbonic anhydrase II (CAII) complexed with the sulfonamide fluorophore 5-dimethylamino-1-naphthalene sulfonamide (dansylamide) has been determined to 2.1-A resolution by x-ray crystallographic methods. Unlike other arylsulfonamide inhibitors of CAII, the naphthyl ring of dansylamide binds in a hydrophobic pocket in the active site, making van der Waals contacts with Val-121, Phe-131, Val-143, Leu-198, and Trp-209. Interestingly, a conformational change of Leu-198 is required to accommodate dansylamide binding, which rationalizes the enhanced dansylamide affinity measured for certain Leu-198 variants (Nair, S. K., Krebs, J.F., Christianson, D. W., and Fierke, C. A. (1995) Biochemistry 34, 3981-3989). Modeling studies indicate that a second binding mode, in which the fused aromatic ring is rotated out of the hydrophobic pocket, is sterically feasible. Both experimentally observed and modeled binding modes have implications for new leads in the design of avid CAII inhibitors. Finally, the structure of the CAII-dansylamide complex has implications for its exploitation in zinc biosensor applications, and possible routes toward the optimization of fluorophore design are considered on the basis on this structure.

Carbonic Anhydrases↗
PubMed1998

Identification of 1,1'-bi(4-anilino)naphthalene-5,5'-disulfonic acid binding sequences in alpha-crystallin.

The hydrophobic binding sites in alpha-crystallin were evaluated using fluorescent probes 1,1'-bi(4-anilino)naphthalenesulfonic acid (bis-ANS), 8-anilino-1-naphthalene sulfonate (ANS), and 1-azidonaphthalene 5-sulfonate (1,5-AZNS). The photolysis of bis-ANS-alpha-crystallin complex resulted in incorporation of the probe to both alphaA- and alphaB-subunits. Prior binding of denatured alcohol dehydrogenase to alpha-crystallin significantly decreased the photoincorporation of bis-ANS to alpha-crystallin. Localization of bis-ANS incorporated into alphaA-crystallin resulted in the identification of residues QSLFR and HFSPEDLTVK as the fluorophore binding regions. In alphaB-crystallin, sequences DRFSVNLNVK and VLGDVIEVHGK were found to be the bis-ANS binding regions. Of the bis-ANS binding sequences, HFSPEDLTVK of alphaA-crystallin and DRFSVNLNVK and VLGDVIEVHGK of alphaB-crystallin were earlier identified as part of the sequences involved in their interaction with target proteins during the molecular chaperone-like action. The hydrophobic probe, 1,5-AZNS, also interacted with both subunits of alpha-crystallin. Localization of 1,5-AZNS binding site in alphaB-crystallin lead to the identification of HFSPEEK sequence as the interacting site in this subunit of alpha-crystallin. Glycated alpha-crystallin displayed decreased ANS fluorescence and loss of chaperone-like function, suggesting the involvement of glycation site as well as ANS binding site in chaperone-like activity display.

Amino Acid Sequence↗
PubMed2005

Controlling {beta}-amyloid oligomerization by the use of naphthalene sulfonates: trapping low molecular weight oligomeric species.

Aggregation of proteins and peptides has been shown to be responsible for several diseases known as amyloidoses, which include Alzheimer disease (AD), prion diseases, among several others. AD is a neurodegenerative disorder caused primarily by the aggregation of beta-amyloid peptide (Abeta). Here we describe the stabilization of small oligomers of Abeta by the use of sulfonated hydrophobic molecules such as AMNS (1-amino-5-naphthalene sulfonate); 1,8-ANS (1-anilinonaphthalene-8-sulfonate) and bis-ANS (4,4'-dianilino-1,1'-binaphthyl-5,5'-disulfonate). The experiments were performed with either Abeta-1-42 or with Abeta-13-23, a shorter version of Abeta that is still able to form amyloid fibrils in vitro and contains amino acid residues 16-20, previously shown to be essential to peptide-peptide interaction and fibril formation. All sulfonated molecules tested were able to prevent Abeta aggregation in a concentration dependent fashion in the following order of efficacy: 1,8-ANS < AMNS < bis-ANS. Size exclusion chromatography revealed that in the presence of bis-ANS, Abeta forms a heterogeneous population of low molecular weight species that proved to be toxic to cell cultures. Since the ANS compounds all have apolar rings and negative charges (sulfonate groups), both hydrophobic and electrostatic interactions may contribute to interpeptide contacts that lead to aggregation. We also performed NMR experiments to investigate the structure of Abeta-13-23 in SDS micelles and found features of an alpha-helix from Lys(16) to Phe(20). 1H TOCSY spectra of Abeta-13-23 in the presence of AMNS displayed a chemical-shift dispersion quite similar to that observed in SDS, which suggests that in the presence of AMNS this peptide might adopt a conformation similar to that reported in the presence of SDS. Taken together, our studies provide evidence for the crucial role of small oligomers and their stabilization by sulfonate hydrophobic compounds.

Amyloid↗
PubMedDate not supplied

Exposure to naphthalene-diisocyanate in a rubber plant: symptoms and lung function.

Twenty-three subjects exposed to naphthalene-diisocyanate (NDI, [mean air concentration 0.002-0.007 mg/m3]) were examined with regard to symptoms and pulmonary function. Irritation of the eyes, cough, and exertion dyspnea were more common in exposed subjects than in unexposed controls. Closing volume, as a percentage of vital capacity (CV%), was 6% higher than the reference value (P = .01) on Monday morning after 2 days with no exposure to NDI. The other lung function variables were normal. Two days of industrial exposure caused no further change in any lung function variable. The difference between measured and expected CV% increased with age in the exposed subjects. Five employees who had complained of severe symptoms during NDI exposure and who, therefore, had been transferred to other tasks with no exposure to NDI, displayed marked increases in CV% and a reduction in the forced vital capacity by an average of 0.6 L. Smokers and nonsmokers displayed similar lung function changes.

Adult↗
PubMedDate not supplied

An outbreak of naphthalene di-isocyanate-induced asthma in a plastics factory.

Seven cases of possible naphthalene di-isocyanate-related occupational asthma occurred in 1987 and 1988. These cases were reported to the National Institute for Occupational Safety and Health by personnel at a Midwest factory that manufactured plastic wheels for fork-lift trucks. The reporting of cases prompted (a) an evaluation of the workplace, including a medical screening of workers, to detect additional cases; and (b) an industrial-hygiene survey to determine the level of exposure to isocyanates.

Adult↗
PubMedDate not supplied

Development, validation and characterization of an analytical method for the quantification of hydrolysable urinary metabolites and plasma protein adducts of 2,4- and 2,6-toluene diisocyanate, 1,5-naphthalene diisocyanate and 4,4'-methylenediphenyl diisocyanate.

Occupational exposure to diisocyanates within the plastic industry causes irritation and disorders in the airway. The aim of this study was to develop, validate and characterize a method for the determination of 2,4-toluenediamine (2,4-TDA), 2,6-toluenediamine (2,6-TDA), 1,5-diaminonaphthalene (1,5-NDA) and 4,4'-methylenedianiline (4,4'-MDA) in hydrolysed urine and plasma, and to study the correlation between the plasma and urinary levels of these potential biomarkers of 2,4-toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate (2,6-TDI), 1,5-naphthalene diisocyanate (1,5-NDI) and 4,4'-methylenediphenyl diisocyanate (4,4'-MDI), respectively. Samples were hydrolysed with 0.3 M NaOH at 100 degrees C for 24 h. The diamines were extracted, derivatized with pentafluoropropionic acid anhydride, and quantified by selected ion monitoring on gas chromatography-mass spectrometry. The repeatability and reproducibility of the method were 7-18% and 7-19%, respectively. Dialysis experiments showed that the metabolites of 2,4-TDI, 2,6-TDI, 1,5-NDI and 4,4'-MDI in plasma were exclusively protein adducts. No free diamines were found in urine, indicating that all diisocyanate-related metabolites were in a conjugated form. For each diisocyanate-related biomarker, there were strongly significant correlations (p<0.001) between individual levels of metabolites in plasma and urine, with Spearman's rank correlation coefficient (rs) values of 0.74-0.90. The methods presented here will be valuable for the development of biological monitoring methods for diisocyanates.

Biomarkers↗
PubMedDate not supplied

Base mutation analysis by a ferrocenyl naphthalene diimide derivative.

An electrochemical DNA sensing technique was developed by using ferrocenyl naphthalene diimide coupled with a probe DNA-immobilized electrode. This technique enabled detection of target DNA quickly and with high sensitivity. Applicability of this technique for single nucleotide polymorphisms (SNPs) analysis was demonstrated by successful analysis of a DNA mismatch on the cancer repression gene p53 with high precision.

DNA↗
PubMed1991

Chemical synthesis of oligonucleotides containing a naphthalene diolepoxide deoxycytidine adduct in solution and using a mixed chemistry semi-automated solid phase approach.

I have recently reported the first total synthesis of a naphthalene diolepoxide--deoxycytidine nucleoside adduct suitable for incorporation into synthetic oligonucleotides. The racemic synthesis yielded the modified deoxycytidine nucleoside as a mixture of diastereomers (1a,b). I now report the conversion of the modified nucleosides (1a,b) into their phosphotriester salts (2a,b) and subsequent incorporation at a specific site into synthetic oligodeoxyribonucleotides. These syntheses yielded oligonucleotides possessing the diastereomerically modified nucleosides, N4-[(+/-)-1(b),2(a),3(a)-trihydroxy-4(b)-1,2,3,4-tetrahydronaphthyl]-2'- deoxycytidine (3a,b = C*), at a specific position. A sample of the modified nucleosides (3a,b) was obtained by chemically removing the protecting groups from (1a,b) and purification on C-18 reverse-phase chromatography. The structure of the modified nucleosides (3a,b) was supported by 400 MHz 1H-NMR and fast atom bombardment MS. The modified tetramers C*pGpApT (9a,b) along with the parent sequence CpGpApT were synthesized using the phosphotriester chemistry in solution. Interestingly, the diastereomerically modified tetramers (9a) and (9b) could be resolved using C-18 reverse-phase chromatography. Using a mixed chemistry semi-automated approach on a solid support the modified oligonucleotide 24mers, ApApTpTpGpCpApApGpTpC*pCpApTpApTpGpGpApCpTpTpGpC (10a,b), were synthesized and purified by anion exchange chromatography. The nucleoside composition of all synthetic oligonucleotides was quantitatively examined by reverse-phase chromatography following enzymic digestion.

Base Sequence↗
PubMed2001

Linker chain effect of ferrocenyl naphthalene diimide on a double stranded DNA preference.

Naphthalene diimide derivative 1 carrying two 3-(ferrocenyl-methylamino)-propyl substituents was synthesized as a new hybrid indicator for electrochemical gene sensing. Ligand 1 showed a preference for double stranded DNA four-times larger than 2 previously described. The peak potential of 1 shifted 30 mV toward the negative side from that of 2, thereby shortening the time required for gene detection.

Biosensing Techniques↗
PubMed2002

Synthesis of adamantyl naphthalene diimide and its interaction with double stranded DNA.

An adamantyl naphthalene diimide derivative (AND) was synthesized as a highly selective double stranded DNA binding reagent. The binding studies with sonicated calf thymus DNA revealed that AND can bind to double stranded DNA by the threading mode, where the two adamantyl moieties are located in the major and minor grooves of DNA duplex separately. In the presence of beta-cyclodextrin (beta-CD), the complex of AND with DNA duplex was stabilized by capping of the adamantyl moieties of AND by beta-CD. In other words, beta-CD serves as a stabilizer for the complex of AND with DNA duplex to result in an enhanced selectivity of AND for double stranded DNA over single stranded DNA.

Adamantane↗
PubMed2000

Ferroceneacetyl naphthalene diimide as a new electrochemical ligand for DNA sensing.

New electrochemically active DNA ligand 1 was synthesized by the connection of ferroceneacetic acid at the terminal amino moieties of two imide substituents of naphthalene diimide. Electrochemical experiments in aqueous solution containing DMSO showed that the selectivity for double stranded DNA of 1 has increased from that of ligand 2 previously reported. The peak current of 1 shifted toward the negative side from that of 2, thereby shortening the time required for gene detection.

DNA↗
PubMed1982

The effects of volatile anesthetics on the binding of 1-anilino-8-naphthalene sulphonate to biological membranes and lipid vesicles: the role of cholesterol.

The effects of volatile anesthetics on the properties of membrane surfaces were studied using the negatively charged fluorescent probe 1-anilino-8-naphthalene sulphonate (ANS). Although the addition of the anesthetics caused no change of the fluorescence quantum yield of ANS bound to the biological membranes, there was a significant increase of the number of binding sites (n) for ANS to the membranes. This increase was also found after treating the membranes with either trypsin or neuraminidase and with vesicles of total lipids extracted from erythrocytes. With phosphatidylcholine (PC) vesicles, the fluorescence increase by the addition of anesthetics was observed only when the vesicle contained cholesterol. The greater increase of the n value was seen in vesicles containing a higher concentration of cholesterol. When the neutral probe, N-phenyl-1-naphthylamine (NPN) was used instead of ANS, this fluorescence increase was not seen. These results were interpreted in terms of the electrostatical change of the membrane lipid region. That is, a change of the surface potential of the membrane is possibly caused by the anesthetics through the interaction with lipid components. Cholesterol plays a critical role in this interaction.

Anesthetics↗
PubMed2001

Polarized infrared spectroscopic study on the orientation of the molecules in the smectic-C* phase of a ferroelectric liquid crystal with a naphthalene ring: alternative theory for the analysis of polarization-angle-dependent intensity changes.

A theory to explain the polarization-angle dependence of polarized infrared spectra of a ferroelectric liquid crystal in the surface-stabilized ferroelectric liquid crystal state is proposed. It describes the relationship between the intensity of the absorption bands and the polarization angle of the infrared radiation. Using this theory the polarization-angle dependence of the infrared band intensities was analyzed for a ferroelectric liquid crystal with a naphthalene ring and two phenyl rings with a stacked layer structure in the smectic-C* phase. The polarization-angle-dependent spectra were measured at 137 degrees C under external dc electric fields of +40 and -40 V to investigate the orientation of the molecules. Plots of the infrared absorbance versus polarization angle for representative bands were subjected to a curve fitting procedure by a least squares method. From the curves obtained the orientation of the transition dipole moments with respect to the molecular long axis and the orientation of the molecular long axis with respect to the rubbing direction of the cell were estimated based upon the suggested theory. The polarization-angle-dependent infrared spectra obtained were also analyzed by two-dimensional (2D) correlation spectroscopy. The 2D correlation analysis clearly detects a slight phase difference in the polarization-angle dependence which is hardly recognized in ordinary plots of the intensity changes in the infrared bands. The 2D correlation analysis allows us to separate asymmetric and symmetric stretching bands due to the chiral methyl group from those arising from other methyl groups in the alkyl chains.

Journal Article↗
PubMed2006

Application of van der Waals density functional to an extended system: adsorption of benzene and naphthalene on graphite.

It is shown that it is now possible to include van der Waals (vdW) interactions via a nonempirical implementation of density functional (DF) theory to describe the correlation energy in electronic structure calculations on infinite systems of no particular symmetry. The vdW-DF theory [Phys. Rev. Lett. 92, 246401 (2004)] is applied to the adsorption of benzene and naphthalene on an infinite sheet of graphite, as well as the binding between two graphite sheets. A comparison with recent thermal-desorption data [Phys. Rev. B 69, 155406 (2004)] shows great promise for the vdW-DF method.

Journal Article↗