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Väre VYP, Eruysal ER, Narendran A, Sarachan KL, Agris PF. Chemical and Conformational Diversity of Modified Nucleosides Affects tRNA Structure and Function. Biomolecules 2017; 7:E29. [PMID: 28300792 PMCID: PMC5372741 DOI: 10.3390/biom7010029] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/06/2017] [Accepted: 03/06/2017] [Indexed: 12/21/2022] Open
Abstract
RNAs are central to all gene expression through the control of protein synthesis. Four major nucleosides, adenosine, guanosine, cytidine and uridine, compose RNAs and provide sequence variation, but are limited in contributions to structural variation as well as distinct chemical properties. The ability of RNAs to play multiple roles in cellular metabolism is made possible by extensive variation in length, conformational dynamics, and the over 100 post-transcriptional modifications. There are several reviews of the biochemical pathways leading to RNA modification, but the physicochemical nature of modified nucleosides and how they facilitate RNA function is of keen interest, particularly with regard to the contributions of modified nucleosides. Transfer RNAs (tRNAs) are the most extensively modified RNAs. The diversity of modifications provide versatility to the chemical and structural environments. The added chemistry, conformation and dynamics of modified nucleosides occurring at the termini of stems in tRNA's cloverleaf secondary structure affect the global three-dimensional conformation, produce unique recognition determinants for macromolecules to recognize tRNAs, and affect the accurate and efficient decoding ability of tRNAs. This review will discuss the impact of specific chemical moieties on the structure, stability, electrochemical properties, and function of tRNAs.
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Affiliation(s)
- Ville Y P Väre
- The RNA Institute, Departments of Biological Sciences and Chemistry, University at Albany, State University of New York, Albany, NY 12222, USA.
| | - Emily R Eruysal
- The RNA Institute, Departments of Biological Sciences and Chemistry, University at Albany, State University of New York, Albany, NY 12222, USA.
| | - Amithi Narendran
- The RNA Institute, Departments of Biological Sciences and Chemistry, University at Albany, State University of New York, Albany, NY 12222, USA.
| | - Kathryn L Sarachan
- The RNA Institute, Departments of Biological Sciences and Chemistry, University at Albany, State University of New York, Albany, NY 12222, USA.
| | - Paul F Agris
- The RNA Institute, Departments of Biological Sciences and Chemistry, University at Albany, State University of New York, Albany, NY 12222, USA.
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Opherden L, Oertel J, Barkleit A, Fahmy K, Keller A. Paramagnetic decoration of DNA origami nanostructures by Eu³⁺ coordination. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:8152-9. [PMID: 24956405 DOI: 10.1021/la501112a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The folding of DNA into arbitrary two- and three-dimensional shapes, called DNA origami, represents a powerful tool for the synthesis of functional nanostructures. Here, we present the first approach toward the paramagnetic functionalization of DNA origami nanostructures by utilizing postassembly coordination with Eu(3+) ions. In contrast to the usual formation of toroidal dsDNA condensates in the presence of trivalent cations, planar as well as rod-like DNA origami maintain their shape and monomeric state even under high loading with the trivalent lanthanide. Europium coordination was demonstrated by the change in Eu(3+) luminescence upon binding to the two DNA origami. Their natural circular dichroism in the Mg(2+)- and Eu(3+)-bound state was found to be very similar to that of genomic DNA, evidencing little influence of the DNA origami superstructure on the local chirality of the stacked base pairs. In contrast, the magnetic circular dichroism of the Mg(2+)-bound DNA origami deviates from that of genomic DNA. Furthermore, the lanthanide affects the magnetic properties of DNA in a superstructure-dependent fashion, indicative of the existence of superstructure-specific geometry of Eu(3+) binding sites in the DNA origami that are not formed in genomic DNA. This simple approach lays the foundation for the generation of magneto-responsive DNA origami nanostructures. Such systems do not require covalent modifications and can be used for the magnetic manipulation of DNA nanostructures or for the paramagnetic alignment of molecules in NMR spectroscopy.
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Affiliation(s)
- Lars Opherden
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf , P.O.B. 510119, 01314 Dresden, Germany
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Garcia J, Kuda-Wedagedara ANW, Allen MJ. Physical Properties of Eu(2+)-Containing Cryptates as Contrast Agents for Ultra-High Field Magnetic Resonance Imaging. Eur J Inorg Chem 2012; 2012:2135-2140. [PMID: 22639543 PMCID: PMC3358779 DOI: 10.1002/ejic.201101166] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Indexed: 11/06/2022]
Abstract
The kinetic stabilities and relaxivities of a series of Eu(2+)-containing cryptates have been investigated. Transmetallation studies that monitored the change in the longitudinal relaxation rate of water protons in the presence of Ca(2+), Mg(2+), and Zn(2+) demonstrated that cryptate structure influences stability, and two of the cryptates studied were inert to transmetallation in the presence of these endogenous ions. The efficacy of these cryptates was determined at different magnetic field strengths, temperatures, and pH values. Cryptate relaxivity was found to be higher at ultra-high field strengths (7 and 9.4 T) relative to clinically relevant field strengths (1.4 and 3 T), but the efficiency of these cryptates decreased as temperature increased. In addition, variation in pH did not yield significant changes in the efficacy of the cryptates. These studies establish a foundation of important properties that are necessary to develop effective positive contrast agents for magnetic resonance imaging from Eu(2+)-containing cryptates.
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Affiliation(s)
- Joel Garcia
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI 48202, USA, Fax: 313-577-8822
| | | | - Matthew J. Allen
- Department of Chemistry, Wayne State University, 5101 Cass Avenue, Detroit, MI 48202, USA, Fax: 313-577-8822
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Yuan F, Griffin L, Phelps L, Buschmann V, Weston K, Greenbaum NL. Use of a novel Förster resonance energy transfer method to identify locations of site-bound metal ions in the U2-U6 snRNA complex. Nucleic Acids Res 2007; 35:2833-45. [PMID: 17430967 PMCID: PMC1888832 DOI: 10.1093/nar/gkm134] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
U2 and U6 snRNAs pair to form a phylogenetically conserved complex at the catalytic core of the spliceosome. Interactions with divalent metal ions, particularly Mg(II), at specific sites are essential for its folding and catalytic activity. We used a novel Förster resonance energy transfer (FRET) method between site-bound luminescent lanthanide ions and a covalently attached fluorescent dye, combined with supporting stoichiometric and mutational studies, to determine locations of site-bound Tb(III) within the human U2-U6 complex. At pH 7.2, we detected three metal-ion-binding sites in: (1) the consensus ACACAGA sequence, which forms the internal loop between helices I and III; (2) the four-way junction, which contains the conserved AGC triad; and (3) the internal loop of the U6 intra-molecular stem loop (ISL). Binding at each of these sites is supported by previous phosphorothioate substitution studies and, in the case of the ISL site, by NMR. Binding of Tb(III) at the four-way junction and the ISL sites was found to be pH-dependent, with no ion binding observed below pH 6 and 7, respectively. This pH dependence of metal ion binding suggests that the local environment may play a role in the binding of metal ions, which may impact on splicing activity.
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Affiliation(s)
| | | | | | | | | | - Nancy L. Greenbaum
- *To whom correspondence should be addressed. +1 850 644 2005+1 850 644 8281
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Horrocks WD, Albin M. Lanthanide Ion Luminescence in Coordination Chemistry and Biochemistry. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/9780470166321.ch1] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
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Mundoma C, Greenbaum NL. Binding of europium(III) ions to RNA stem loops: role of the primary hydration sphere in complex formation. Biopolymers 2003; 69:100-9. [PMID: 12717725 DOI: 10.1002/bip.10320] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Understanding the process by which RNA molecules fold into stable structures includes study of the role of site-bound metal ions. Because the alkaline earth metal ions typically associated with RNA structure [most often Mg(II)] do not provide convenient spectroscopic signals, replacement with metal ions having spectroscopically useful properties has been a valuable approach. The luminescence properties of the lanthanide(III) series, in particular europium(III), have made them useful in the study of complexation with biomolecules. We review the physical, chemical, and spectroscopic characteristics of Eu(III) that contribute to its value as a probe of RNA-metal ion interactions, and examples of information obtained from studies of Eu(III) bound to small RNA stem loops. Although Eu(III) has similar site preference to Mg(II), luminescence and isothermal titration calorimetry measurements indicate that Ln(III) loses water molecules from the inner hydration sphere more readily than does Mg(II), resulting in more direct coordination between RNA and the metal ion and very different energetics of binding. In some cases, e.g., a GAAA tetraloop, binding appears to occur by a lock and key process; in the same base sequence containing certain deoxynucleoside substitutions that alter loop structure, binding appears to occur by an induced fit process.
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Affiliation(s)
- Claudius Mundoma
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee 32306-4390, USA
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Hargittai MR, Mangla AT, Gorelick RJ, Musier-Forsyth K. HIV-1 nucleocapsid protein zinc finger structures induce tRNA(Lys,3) structural changes but are not critical for primer/template annealing. J Mol Biol 2001; 312:985-97. [PMID: 11580244 DOI: 10.1006/jmbi.2001.5021] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Retroviral reverse transcriptases use host cellular tRNAs as primers to initiate reverse transcription. In the case of human immunodeficiency virus type 1 (HIV-1), the 3' 18 nucleotides of human tRNA(Lys,3) are annealed to a complementary sequence on the RNA genome known as the primer binding site (PBS). The HIV-1 nucleocapsid protein (NC) facilitates this annealing. To understand the structural changes that are induced upon NC binding to the tRNA alone, we employed a chemical probing method using the lanthanide metal terbium. At low concentrations of NC, the strong terbium cleavage observed in the core region of the tRNA is significantly attenuated. Thus, NC binding first results in disruption of the tRNA's metal binding pockets, including those that stabilize the D-TPsiC tertiary interaction. When NC concentrations approach the amount needed for complete primer/template annealing, NC further destabilizes the tRNA acceptor-TPsiC stem minihelix, as evidenced by increased terbium cleavage in this domain. A mutant form of NC (SSHS NC), which lacks the zinc finger structures, is able to anneal tRNA(Lys,3) efficiently to the PBS, and to destabilize the tRNA tertiary core, albeit less effectively than wild-type NC. This mutant form of NC does not affect cleavage significantly in the helical regions, even when bound at high concentrations. These results, as well as experiments conducted in the presence of polyLys, suggest that in the absence of the zinc finger structures, NC acts as a polycation, neutralizing the highly negative phosphodiester backbone. The presence of an effective multivalent cationic peptide is sufficient for efficient tRNA primer annealing to the PBS.
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Affiliation(s)
- M R Hargittai
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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Abstract
Divalent metal ions are absolutely required for the structure and catalytic activities of ribosomes. They are partly coordinated to highly structured RNA, which therefore possesses high-affinity metal ion binding pockets. As metal ion induced RNA cleavages are useful for characterising metal ion binding sites and RNA structures, we analysed europium (Eu3+) induced specific cleavages in both 16S and 23S rRNA of E. coli. The cleavage sites were identified by primer extension and compared to those previously identified for calcium, lead, magnesium, and manganese ions. Several Eu3+ cleavage sites, mostly those at which a general metal ion binding site had been already identified, were identical to previously described divalent metal ions. Overall, the Eu3+ cleavages are most similar to the Ca2+ cleavage pattern, probably due to a similar ion radius. Interestingly, several cleavage sites which were specific for Eu3+ were located in regions implicated in the binding of tRNA and antibiotics. The binding of erythromycin and chloramphenicol, but not tetracycline and streptomycin, significantly reduced Eu3+ cleavage efficiencies in the peptidyl transferase center. The identification of specific Eu3+ binding sites near the active sites on the ribosome will allow to use the fluorescent properties of europium for probing the environment of metal ion binding pockets at the ribosome's active center.
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Affiliation(s)
- S Dorner
- Institut für Biochemie, Universität Wien, Vienna Biocenter, Austria
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Feig AL, Scott WG, Uhlenbeck OC. Inhibition of the hammerhead ribozyme cleavage reaction by site-specific binding of Tb. Science 1998; 279:81-4. [PMID: 9417029 DOI: 10.1126/science.279.5347.81] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Terbium(III) [Tb(III)] was shown to inhibit the hammerhead ribozyme by competing with a single magnesium(II) ion. X-ray crystallography revealed that the Tb(III) ion binds to a site adjacent to an essential guanosine in the catalytic core of the ribozyme, approximately 10 angstroms from the cleavage site. Synthetic modifications near this binding site yielded an RNA substrate that was resistant to Tb(III) binding and capable of being cleaved, even in the presence of up to 20 micromolar Tb(III). It is suggested that the magnesium(II) ion thought to bind at this site may act as a switch, affecting the conformational changes required to achieve the transition state.
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Affiliation(s)
- A L Feig
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309, USA
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Agris PF, Brown SC. Systems for the NMR study of modified nucleoside-dependent, metal-ion induced conformational changes in nucleic acids. Methods Enzymol 1995; 261:270-99. [PMID: 8569499 DOI: 10.1016/s0076-6879(95)61014-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- P F Agris
- Department of Biochemistry, North Carolina State University, Raleigh 27695, USA
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Affiliation(s)
- W D Horrocks
- Department of Chemistry, Pennsylvania State University, University Park 16802
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Kido J, Okamoto Y, Yoshioka N, Nishide H, Tsuchida E. Effect of ultrasonic irradiation on luminescence properties of lanthanide-polyelectrolyte complexes. POLYMER 1992. [DOI: 10.1016/0032-3861(92)90516-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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15
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Soans C, Fromm HJ. Studies of ligand binding to Escherichia coli adenylosuccinate synthetase. Arch Biochem Biophys 1991; 291:107-12. [PMID: 1929424 DOI: 10.1016/0003-9861(91)90111-u] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Dissociation constants of Escherichia coli adenylosuccinate synthetase with IMP, GTP, adenylosuccinate, and AMP (a competitive inhibitor for IMP) were determined by measuring the extent of quenching of the intrinsic tryptophan fluorescence of the enzyme. The enzyme has one binding site for each of these ligands. Aspartate and GDP did not quench the fluorescence to any great extent, and their dissociation constants could not be determined. These ligand binding studies were generally supportive of the kinetic mechanism proposed earlier for the enzyme. Cys291 was modified with the fluorescent chromophores N-(iodoacetylaminoethyl)-5-naphthylamine-1-sulfonate and tetramethylrhodamine maleimide in order to measure enzyme conformational changes attending ligand binding. The excitation and emission spectra of these fluorophores are not altered by the addition of active site binding ligands. TbGTP and TbGDP were used as native reporter groups, and changes in their fluorescence on complexing with the enzyme and various ligands made it possible to detect conformational changes occurring at the active site. Evidence is presented for abortive complexes of the type: enzyme-TbGTP-adenylosuccinate and enzyme-TbGTP-adenylosuccinate-aspartate. These results suggest that the IMP and aspartate binding sites are spatially separated.
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Affiliation(s)
- C Soans
- Department of Biochemistry and Biophysics, Iowa State University, Ames 50011
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Ligner G, Mohan R, Knittel S, Duportail G. Hypersensitivity of terbium and europium ions luminescence in biological substrates. ACTA ACUST UNITED AC 1990. [DOI: 10.1016/0584-8539(90)80037-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Ciesiołka J, Marciniec T, Krzyzosiak W. Probing the environment of lanthanide binding sites in yeast tRNA(Phe) by specific metal-ion-promoted cleavages. EUROPEAN JOURNAL OF BIOCHEMISTRY 1989; 182:445-50. [PMID: 2661230 DOI: 10.1111/j.1432-1033.1989.tb14851.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Specific yeast tRNA(Phe) hydrolysis brought about by europium ions has been studied in detail using the 32P-end-labeled tRNA and polyacrylamide gel electrophoresis. The dependence of the induced cleavages on pH, temperature and concentration of the europium ions has been determined. Europium hydrolyzes yeast tRNA(Phe) in the D-loop at phosphates 16 and 18, and the anticodon loop of phosphates 34 and 36. The two D-loop cuts are thought to take place from two distinct europium binding sites, while the two anticodon loop cleavages from a single site. Eight other members of the lanthanide series and ytrium give basically the same pattern of cleavages as europium. The specific cleavages taking place in the anticodon loop occur in an intramolecular mode from the lanthanide binding site that has not been found in yeast tRNA(Phe) crystal structure. It appears from the comparison of the europium-promoted cuts with those generated by magnesium and lead that the former two ions give more similar but not identical cleavage patterns. The usefulness of the specific cleavages induced by lanthanides for probing their own and magnesium binding sites in tRNA is discussed.
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Affiliation(s)
- J Ciesiołka
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań
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Wenzel TJ, Collette LM. Lanthanide ions as luminescent chromophores for the liquid chromatographic detection of polynucleotides and nucleic acids. J Chromatogr A 1988; 436:299-307. [PMID: 3356764 DOI: 10.1016/s0021-9673(00)94587-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Europium(III) and terbium(III) can be used as luminescent chromophores for the liquid chromatographic detection of certain nucleotides and nucleic acids. The method is dependent upon an energy transfer from the nucleic acid to the lanthanide ion. Of the base moieties, only xanthine, guanine, and thiouridine have appropriate excited state energy levels for efficient energy transfer. The lanthanide ion can be added in a pre- or post-column mode. The applicability of the method was demonstrated for the detection of homologous polynucleotides such as poly X and poly G. The method was also used to detect transfer RNA from Escherichia coli.
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Affiliation(s)
- T J Wenzel
- Department of Chemistry, Bates College, Lewiston, ME 04240
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Soini E, Lövgren T, Reimer CB. Time-Resolved Fluorescence of Lanthanide Probes and Applications in Biotechnology. ACTA ACUST UNITED AC 1987. [DOI: 10.1080/10408348708542802] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Chatterji D. Terbium(III)-induced conformational transition in poly(dG-dC) fluorescence and circular dichroic studies. FEBS Lett 1986; 203:54-8. [PMID: 3720957 DOI: 10.1016/0014-5793(86)81435-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Poly(dG-dC) in 60% aqueous alcohol exhibits the characteristic inversion of the circular dichroism spectrum associated with the formation of left-handed helix. Upon complexation with Tb3+, poly(dG-dC) in this medium induces marked enhancement of the Tb(III) fluorescence emission at 488 and 545 nm, when excited at 290 nm. The degree of fluorescence enhancement is dependent on the concentration of Tb(III) at a fixed poly(dG-dC) concentration. Neither poly(dG-dC) in water nor poly(dA-dT) in water or 60% alcohol, causes any significant fluorescence spectral changes of Tb3+. Tb(III)-poly(dG-dC) in 60% alcohol shows circular dichroic spectra associated with a broad positive molar ellipticity ranging from 6000 to 10 000 degree X cm2 X dmol-1 between 270 and 280 nm, and a small negative band around 240 nm.
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Abstract
The luminescence properties of Eu3+ have been used to investigate the binding and coordination properties of the ion with tRNA, as an attempt to resolve the discussion of whether metal ions bind to tRNA in solution only by Debye-Hückel screening, or whether direct coordination to specific sites may occur. Binding studies with Escherichia coli tRNAmet/f (taking advantage of 4-thiouracil-sensitized Eu3+ emission) distinguish three classes of binding affinities. Two of these are single sites with affinities approx. 10(4) and approx. 10(3) tighter than the nonspecific affinity of Eu3+ for native DNA. Mg2+ competes for binding at both these sites. Measurement of the lifetime and excitation spectrum of Eu3+ bound to the highest affinity site shows that the ion has two to five non-phosphate ligands in its inner coordination sphere. The existence of this coordinated site demonstrates that electrostatic screening is not the only mechanism for metal ion interaction with tRNA. The coordination properties of the high-affinity Eu3+ site do not agree with the properties of any of the metal ion sites found in the two tRNAphe crystal forms. Possible reasons for this discrepancy are discussed; it may be that ions bind differently to isolated molecules in solution than to molecules packed in a crystal lattice.
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Abusaleh A, Meares CF. Excitation and de-excitation processes in lanthanide chelates bearing aromatic sidechains. Photochem Photobiol 1984; 39:763-9. [PMID: 6431456 DOI: 10.1111/j.1751-1097.1984.tb08856.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Haertlé T, Augustyniak J, Guschlbauer W. Is Tb3+ fluorescence enhancement only due to binding to single stranded polynucleotides. Nucleic Acids Res 1981; 9:6191-7. [PMID: 7312634 PMCID: PMC327593 DOI: 10.1093/nar/9.22.6191] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Enhancement of Tb3+ fluorescence upon binding to double-stranded ribo- and deoxyribo-duplexes was investigated. It was observed that certain double stranded ribopolynucleotides completely quenched the Tb3+ fluorescence and others did not. It is concluded that the nature of the base in the duplex is critical for this enhancement. - Polydeoxyduplexes also showed enhancement of Tb3+ fluorescence, but much higher terbium concentrations were necessary to obtain similar fluorescence signals, indicative of unspecific effects. CD spectra evidence considerable conformational changes of these duplexes, in particular poly(dG-C) . poly(dG-C( which assumes the Z-form in 0.1 nM Tb3+.
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Morley PJ, Martin RB, Boatman S. Characterization of excitation spectra for Tb3+ luminescence from nucleic acids: calcium binding environs in icosahedral viruses. Biochem Biophys Res Commun 1981; 101:1123-30. [PMID: 6171279 DOI: 10.1016/0006-291x(81)91564-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Abstract
Calcium ion plays an essential role in many biological processes. The environment about Ca2+may be probed by substitution of tripositive lanthanide ions, Ln3+. Ca2+proteins fall into two broad classes: those that are inhibited by Ln3+substitution and those that are not. It is suggested that although Ca2+undertakes a primarily structural role in the Ln3+non-inhibited proteins, Ca2+may be near the active site or participate in the mechanism of action of Ln3+inhibited proteins. Ca2+and Ln3+radii are similar; most Ln3+are slightly larger than Ca2+in complexes of the same coordination number, and substitution of Ln3+for Ca2+is accommodated by a slight decrease in bond distance or by an increase in coordination number. Luminescence from Tb3+has been demonstrated to be a sensitive environmental probe of Ca2+binding sites in proteins.
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Chapter 39 Bioinorganic chemistry: Lanthanides as probes in systems of biological interest. ACTA ACUST UNITED AC 1979. [DOI: 10.1016/s0168-1273(79)04018-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Holler E. Protein biosynthesis: the codon-specific activation of amino acids. ANGEWANDTE CHEMIE (INTERNATIONAL ED. IN ENGLISH) 1978; 17:648-56. [PMID: 101100 DOI: 10.1002/anie.197806481] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Grinvald A, Yaari Y. Utilization of fluorescent lanthanide ions for the study of cation binding to extracellular sites in frog skeletal muscle. Life Sci 1978; 22:1573-83. [PMID: 307641 DOI: 10.1016/0024-3205(78)90051-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Rordorf BF, Kearns DR. Effects of europium (III) on the thermal denaturation and cleavage of transfer ribonucleic acids. Biopolymers 1976; 15:1491-504. [PMID: 786405 DOI: 10.1002/bip.1976.360150805] [Citation(s) in RCA: 42] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Horrocks WD, Holmquist B, Vallee BL. Energy transfer between terbium (III) and cobalt (II) in thermolysin: a new class of metal--metal distance probes. Proc Natl Acad Sci U S A 1975; 72:4764-8. [PMID: 1061067 PMCID: PMC388811 DOI: 10.1073/pnas.72.12.4764] [Citation(s) in RCA: 75] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The visible fluorescence of terbium(III) when bound to a calcium binding site of thermolysin is greatly enhanced with an excitation maximum at 280 nm but substitution of cobalt(II) for zinc at the active site decreases the intensity by 89.5%. Treatment with N-bromosuccinimide quenches enzyme tryptophan and Tb(III) fluorescence to a similar extent and suggests the operation of tryptophan vector Tb(III) vector Co(II) energy relay system in the enzyme. Dipoledipole radiationless energy transfer between the Tb(III) donor and the Co(II) acceptor can account for this quenching. The inherent characteristics of the metal pair limits the value of the orientation factor, K2, of the Förster equation, thereby reducing uncertainties in distance measurements by energy transfer compared with other systems. A quantum yield of 0.51 yields a value of R0, the distance for 50% energy transfer, of 19.6 A, and a distance, R, between Tb(III) and Co(II) of 13.7 A, a value identical to that measured for the distance between the active site zinc atom and calcium atom number 1 by x-ray analysis in native thermolysin crystals. The limits of confidence of this measurement are discussed. Energy transfer between two different metal atom sites of a protein provides a new class of probes to measure intramolecular distances of biological macromolecules in solution.
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