The synthesis, proof of structure, and the absorption fluorescence properties two new unsymmetrical cyanine dyes, thiazole orange dimer (TOTO; 1,1 '- (4,4,7,7-tetramethyl-4,7-diazaundecamethylene)-bis-4-[3-methyl-2,3-dihydro-(benzo-1 ,3-thiazole)-2-methylidene]-quinolinium tetraiodide) oxazole yellow (YOYO; an analogue TOTO with a benzo-1,3- in place benzo-1,3-thiazole) are reported.TOTO YOYO virtually non-fluorescent solution, but form highly fluorescent complexes double-stranded DNA...

An active site, cofactor-containing peptide has been obtained in high yield from bovine serum amine oxidase. Sequencing of this pentapeptide indicates: Leu-Asn-X-Asp-Tyr. Analysis the by mass spectrometry, ultraviolet-visible spectroscopy, and proton nuclear magnetic resonance leads to identification X as 6-hydroxydopa. This result indicates that, contrary previous proposals, pyrroloquinoline quinone is not site cofactor mammalian copper oxidases. Although 6-hydroxydopa implicated...

Protein actions are usually discussed in terms of static structures, but function requires motion. We find a strong correlation between phosphorylation-driven activation the signaling protein NtrC and microsecond time-scale backbone dynamics. Using nuclear magnetic resonance relaxation, we characterized motions three functional states: unphosphorylated (inactive), phosphorylated (active), partially active mutant. These dynamics indicative exchange inactive conformations. Both states...

Dimerization-driven activation of the intracellular kinase domains epidermal growth factor receptor (EGFR) upon extracellular ligand binding is crucial to cellular pathways regulating proliferation, migration, and differentiation. Inactive EGFR can exist as both monomers dimers, suggesting that mechanism activity may be subtle. The membrane itself play a role but creates substantial difficulties for structural studies. Our molecular dynamics simulations membrane-embedded suggest that, in...

A magnetic resonance approach is presented that enables high-sensitivity, high-contrast molecular imaging by exploiting xenon biosensors. These sensors link atoms to specific biomolecular targets, coupling the high sensitivity of hyperpolarized nuclei with specificity biochemical interactions. We demonstrated spatial resolution a target protein in vitro at micromolar concentration, readout scheme reduces required acquisition time >3300-fold relative direct detection. This technique uses...

Two-dimensional NMR has been used to study the 2:1 distamycin A.d(CGCAAATTGGC).d(GCCAATTTGCG) complex. The nuclear Overhauser effect spectroscopy (NOESY) experiment was assign aromatic and C1'H DNA protons identify drug-DNA contacts. These data indicate that two drug molecules bind simultaneously in minor groove of central 5'-AAATT-3' segment are close contact with both one another. One binds formyl end second adenine base A-rich strand, while other complementary strand. With this binding...

Methylamine dehydrogenase (MADH), an α 2 β enzyme from numerous methylotrophic soil bacteria, contains a novel quinonoid redox prosthetic group that is covalently bound to its small subunit through two amino acyl residues. A comparison of the acid sequence deduced gene for Methylobacterium extorquens AM1 with published obtained by Edman degradation method, allowed identification constituents cofactor as tryptophyl This information was crucial interpreting 1 Hand 13 C nuclear magnetic...

The excitation and detection of multiple quantum transitions in systems coupled spins offers, among other advantages, an increase resolution over single n.m.r. since the number lines decreases as order transition increases. This paper reviews motivation for detecting by a Fourier transform experiment describes experimental approach to high spectra dipolar along with results on some protonated liquid crystal systems. A simple operator formalism essential features time development is presented...

Miscanthus giganteus lignin was extracted by an organosolv process under reflux conditions (4 h) with varying concentrations of ethanol (65%, 75%, 85%, 95%) and 0.2 M hydrochloric acid as catalyst. The resulting extensively characterized size exclusion chromatography (SEC), Fourier-transform infrared spectroscopy (FTIR), gas chromatography-mass spectrometry (GC/MS), two-dimensional nuclear magnetic resonance (2D-NMR), chemical analysis (residual sugars, Klason lignin, ash). predominant...

The detection of biological molecules and their interactions is a significant component modern biomedical research. In current biosensor technologies, simultaneous limited to small number analytes by the spectral overlap signals. We have developed an NMR-based xenon that capitalizes on enhanced signal-to-noise, simplicity, chemical-shift sensitivity laser-polarized detect specific biomolecules at level tens nanomoles. present results using “functionalized” biotin-modified supramolecular cage...

We show that a transient lactic fermentation provides the signal triggering ethanol production in hypoxic maize root tips. The is cytoplasmic pH. This interaction between and ethanolic permits tight pH regulation during hypoxia--cytoplasmic remaining near neutrality for several hours. Mutant roots unable to synthesize can neither regulate nor maintain ATP levels extended periods of hypoxia and, like vertebrate tissues, are less tolerant than normal maize. indicates an important factor...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBinding modes of distamycin A with d(CGCAAATTTGCG)2 determined by two-dimensional NMRJeffrey G. Pelton and David E. WemmerCite this: J. Am. Chem. Soc. 1990, 112, 4, 1393–1399Publication Date (Print):February 1, 1990Publication History Published online1 May 2002Published inissue 1 February 1990https://pubs.acs.org/doi/10.1021/ja00160a016https://doi.org/10.1021/ja00160a016research-articleACS PublicationsRequest reuse permissionsArticle...

Transcription by σ 54 RNA polymerase depends on activators that contain ATPase domains of the AAA + class. These activators, which are often response regulators two-component signal transduction systems, remodel so it can form open complexes at promoters. Here, we report first crystal structures domain an activator, NtrC1 protein from extreme thermophile Aquifex aeolicus . This alone, is active, crystallized as a ring-shaped heptamer. The carrying both and adjacent receiver domains,...

A four-ring tripeptide containing alternating imidazole and pyrrole carboxamides specifically binds six-base pair 5′-(A,T)GCGC(A,T)-3′ sites in the minor groove of DNA. The designed peptide has a specificity completely reversed from that tripyrrole distamycin, which A,T sequences. Structural studies with nuclear magnetic resonance revealed two peptides bound side-by-side an antiparallel orientation groove. Each four imidazoles 2:1 ligand-DNA complex recognized specific guanine amino group...

The designed peptide 1-methylimidazole-2-carboxamide netropsin (2-ImN) binds specifically to the sequence 5'-TGACT-3'. Direct evidence from NMR spectroscopy is presented that this synthetic ligand DNA as a 2:1 complex, which reveals structure an antiparallel dimer in minor groove of DNA. This contrast 1:1 complexes usually seen with most crescent-shaped binding molecules targeted toward A+T-rich tracts but reminiscent dimeric motif found for distamycin at high concentrations. These results...

We combine molecular dynamics simulations and new high-field NMR experiments to describe the solution structure of Aβ21–30 peptide fragment that may be relevant for understanding structural mechanisms related Alzheimer's disease. By using two different empirical force-field combinations, we provide predictions three-bond scalar coupling constants (3JHNHα), chemical-shift values, 13C relaxation parameters, rotating-frame nuclear Overhauser effect spectroscopy (ROESY) crosspeaks can then...

Background: The development of cost-competitive biofuels necessitates the realization advanced biomass pretreatment technologies. Ionic liquids provide a basis for one most promising technologies and are known to allow effective processing cellulose some species. Results & discussion: Here, we demonstrate that ionic liquid 1-ethyl-3-methyl imidazolium acetate, [C2mim][OAc], induces structural changes at molecular level in cell wall Eucalyptus globulus. Deacetylation xylan, acetylation lignin...

The interplay of modern molecular simulation and high-quality nuclear magnetic resonance (NMR) experiments has reached a fruitful stage for quantitative characterization structural ensembles disordered peptides. Amyloid-β 1-42 (Aβ42), the primary peptide associated with Alzheimer's disease, fragments such as Aβ21-30 are both classified intrinsically peptides (IDPs). We use variety NMR observables to validate de novo dynamics simulations in explicit water characterize tertiary structure...