A cationic lanthanide complex binds selectively to phosphorylated tyrosine sites, aiding NMR analysis of the phosphorylated insulin receptor peptide fragment
03 Aug 2006-Organic and Biomolecular Chemistry (The Royal Society of Chemistry)-Vol. 4, Iss: 16, pp 3166-3171
TL;DR: Analysis of the europium emission and NMR spectral data was consistent with the presence of species in slow exchange on the NMR and emission timescales, in agreement with selective binding of the lanthanide ion to the phospho-tyrosine site, allowing such complexes to be considered as prototypical chemoselective paramagnetic derivatising agents.
Abstract: The binding of two cationic europium complexes to a differentially phosphorylated insulin receptor peptide has been studied by emission spectroscopy and 31P NMR and 1H NMR TOCSY methods. Analysis of the europium emission and NMR spectral data was consistent with the presence of species in slow exchange on the NMR and emission timescales, in agreement with selective binding of the lanthanide ion to the phospho-tyrosine site, allowing such complexes to be considered as prototypical chemoselective paramagnetic derivatising agents.
Citations
More filters
TL;DR: Changes in anion concentration can be monitored rapidly, accurately and with high spatial resolution using optical emission spectroscopy and microscopy, facilitating the measurement of anions such as bicarbonate, lactate, citrate and urate in a variety of bio-fluids.
Abstract: Reversible anion binding at lanthanide centres in aqueous media has emerged as an effective means of signalling and sensing the presence of selected anions. The constitution and configuration of a wide range of anion adducts has been defined by X-ray analyses and NMR methods, and both chelating and monodentate binding modes characterised. Variation of the lanthanide ion modulates charge density, and ligand modification allows alteration of both the peripheral electrostatic gradient and the local steric demand at the metal centre. Thus, selectivity for a target anion can be engineered, and the affinity constant modulated to target the desired concentration range. Changes in anion concentration can be monitored rapidly, accurately and with high spatial resolution using optical emission spectroscopy and microscopy, facilitating the measurement of anions such as bicarbonate, lactate, citrate and urate in a variety of bio-fluids.
276 citations
01 Jan 2007
TL;DR: In this article, the fundamental concepts of how to produce lanthanide complexes that can have their luminescence properties manipulated by external sources are discussed, followed by a review of selected examples from the recent literature.
Abstract: This article is concerned with the recent advantages in the design of lanthanide complexes as luminescent devices such as sensors and switches. Herein the fundamental concepts of how to produce lanthanide complexes that can have their luminescence properties manipulated by external sources is first discussed, followed by a review of selected examples from the recent literature.
144 citations
TL;DR: Lanthanide-based Luminescent probes TPR1 and TPR2 were developed for the detection of hydrogen peroxide in living systems and the chemoselective reaction of these boronate-protected probes resulted in an enhanced lanthanide sensitization and a 6-fold increase in luminescent intensity.
109 citations
TL;DR: A series of experiments has been undertaken in order to gain a greater understanding of the cellular uptake and localisation behaviour of emissive lanthanide complexes as cellular stains or probes, and a common uptake mechanism of macropinocytosis has been identified.
Abstract: A series of experiments has been undertaken in order to gain a greater understanding of the cellular uptake and localisation behaviour of emissive lanthanide complexes as cellular stains or probes. Out of a large number of structurally related complexes characterised recently, a set of seven representative examples has been examined in detail, containing either tetraazatriphenylene or azaxanthone-based sensitising chromophores. Intracellular localisation profiles and cellular uptake and egress behaviour have been studied by microscopy and flow cytometry. Typically, the maximum intracellular concentration was of the order of 0.4 mM, or about 109 complexes per cell. The complexes studied were generally not toxic and did not perturb the mitochondrial membrane potential. A common uptake mechanism of macropinocytosis has been identified. A generalisation of trends in behaviour, and structure–activity relationships is presented, and the implications for future probe design discussed.
108 citations
TL;DR: The homoditopic ligand 6,6'-[methylenebis(1-methyl-1H-benzimidazole-5,2-diyl)]bis(4-{2-[2-methoxyethoxy)ethoxy]ethoxy}pyridine-2-carboxylic acid) (H(2)L(C2)) has been tailored to self-assemble with lanthanide ions (Ln(III),
Abstract: The homoditopic ligand 6,6’- [methylenebis(1-methyl-1H-benzimid- azole-5,2-diyl)]bis(4-{2-[2-(2-methoxy- ethoxy)ethoxy]ethoxy}pyridine-2-carboxylic acid) (H2LC2) has been tailored to self-assemble with lanthanide ions (LnIII), which results in the formation of neutral bimetallic helicates with the overall composition [Ln2(LC2)3] and also provides a versatile platform for further derivatization. The grafting of poly(oxyethylene) groups onto the pyridine units ensures water solubility, while maintaining sizeable thermodynamic stability and adequate antenna effects for the excitation of both visible- and NIR-emitting LnIII ions. The conditional stability constants (logb23) are close to 25 at physiological pH and under stoichiometric conditions. The ligand triplet state features adequate energy (0-phonon transition at 21 900 cm-1) to sensitize the luminescence of EuIII (Q=21%) and TbIII (11%) in aerated water at pH 7.4. The emission of several other VIS- and NIR-emitting ions, such as SmIII (Q=0.38%) or YbIII (0.15%), for which in cellulo luminescence is evidenced for the first time, is also sensitized. The EuIII emission spectrum arises from a main species with pseudo-D3 symmetry and without coordinated water. The cell viability of several cancerous cell lines (MCF-7, HeLa, Jurkat and 5D10) is unaffected if incubated with up to 500 mm [Eu2(LC2)3] during 24 h. Bright EuIII emission is seen for incubation concentrations above 10 mm and after a 15-minute loading time; similar images are obtained with TbIII and SmIII. The helicates probably permeate into the cytoplasm of HeLa cells by endocytosis. The described luminescent helical stains are robust chemical species which remain undissociated in the cell medium and in presence of other complexing agents, such as edta, dtpa, citrate or l-ascorbate. Their derivatization, which would open the way to the sensing of targeted in cellulo phenomena, is currently under investigation.
102 citations
References
More filters
TL;DR: The 2D NOE experiment has the principal advantage that it avoids detrimental effects arising from the limited selectivity of preirradiation in crowded spectral regions, and yields with a single instrument setting a complete network of NOE's between all the protons in the macromolecule.
1,842 citations
TL;DR: This tutorial review covers imidazolium receptors for anion recognition according to their topological and structural classification, and includes benzene tripodal, cyclophane and calix-imidazolate, ferrocenyl imidzolium, cavitand and Calixarene, and polymeric imidAZolium systems.
Abstract: This tutorial review covers imidazolium receptors for anion recognition according to their topological and structural classification, and includes benzene tripodal, cyclophane and calix-imidazolium, fluorescent imidazolium, ferrocenyl imidazolium, cavitand and calixarene, and polymeric imidazolium systems.
748 citations
TL;DR: In this paper, a review traces the emergence of pyrrole-based receptors for anion recognition and outlines how serendipitous findings that the diprotonated form of sapphyrin formed a centrally-bound complex with fluoride anion spawned studies of this and other expanded porphyrins as receptors, carriers, and sensors of anions, including the finding that neutral, non-aromatic oligopyrrole macrocycles, such as the calixpyrroles and calixphyrins, can act as cheap, and easy-to
710 citations
TL;DR: A general scheme that relies on experimental observation by two-dimensional nuclear magnetic resonance techniques of complete throughbond and through-space proton-proton connectivity maps to obtain sequential resonance assignments for the individual residues in the amino acid sequence is proposed.
541 citations
TL;DR: Anions are ubiquitous species, and therefore, their sensing is of considerable interest as mentioned in this paper, which is why anion receptors containing electrochemically active groups such as ferrocene or cobaltocenium, or optically active group such as ruthenium(II) bipyridyl derivatives, allow the binding of anions to be detected by a physical response at the metal center.
521 citations