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Masaki Y, Sekine M, Seio K. Deformability Calculation for Estimation of the Relative Stability of Chemically Modified RNA Duplexes. ACTA ACUST UNITED AC 2017; 68:7.27.1-7.27.10. [PMID: 28252179 DOI: 10.1002/cpnc.25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Chemical modification of RNA duplexes alters their stability. We have attempted to develop a computational approach to estimate the thermal stability of chemically modified duplexes. These studies revealed that the deformability of chemically modified RNA duplexes, calculated from molecular dynamics simulations, could be used as a good indicator for estimating the effect of chemical modification on duplex thermal stability. This unit describes how deformability calculation can be applied to estimate the relative stability of chemically modified RNA duplexes. © 2017 by John Wiley & Sons, Inc.
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Seio K, Ohno Y, Ohno K, Takeshita L, Kanamori T, Masaki Y, Sekine M. Photo-controlled binding of MutS to photo-caged DNA duplexes incorporating 4- O -(2-nitrobenzyl) or 4- O -[2-(2-nitrophenyl)propyl]thymidine. Bioorg Med Chem Lett 2016; 26:4861-4863. [DOI: 10.1016/j.bmcl.2016.07.075] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 07/14/2016] [Accepted: 07/29/2016] [Indexed: 10/21/2022]
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Asami H, Tokugawa M, Masaki Y, Ishiuchi SI, Gloaguen E, Seio K, Saigusa H, Fujii M, Sekine M, Mons M. Effective Strategy for Conformer-Selective Detection of Short-Lived Excited State Species: Application to the IR Spectroscopy of the N1H Keto Tautomer of Guanine. J Phys Chem A 2016; 120:2179-84. [DOI: 10.1021/acs.jpca.6b01194] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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29
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Tokugawa M, Masaki Y, Canggadibrata JC, Kaneko K, Shiozawa T, Kanamori T, Grøtli M, Wilhelmsson LM, Sekine M, Seio K. 7-(Benzofuran-2-yl)-7-deazadeoxyguanosine as a fluorescence turn-ON probe for single-strand DNA binding protein. Chem Commun (Camb) 2016; 52:3809-12. [DOI: 10.1039/c5cc09700b] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
7-(Benzofuran-2-yl)-7-deazadeoxyguanosine (BFdG) was synthesized and incorporated into an oligodeoxynucleotide (ODN).
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Ito Y, Masaki Y, Kanamori T, Ohkubo A, Seio K, Sekine M. Synthesis of 5-[3-(2-aminopyrimidin-4-yl)aminopropyn-1-yl]uracil derivative that recognizes Ade-Thy base pairs in double-stranded DNA. Bioorg Med Chem Lett 2016; 26:194-6. [PMID: 26602276 DOI: 10.1016/j.bmcl.2015.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 10/30/2015] [Accepted: 11/02/2015] [Indexed: 11/28/2022]
Abstract
5-[3-(2-Aminopyrimidin-4-yl)aminopropyn-1-yl]uracil (Ura(Pyr)) was designed as a new nucleobase to recognize Ade-Thy base pair in double-stranded DNA. We successfully synthesized the dexoynucleoside phosphoramidite having Ura(Pyr) and incorporated it into triplex forming oligonucleotides (TFOs). Melting temperature analysis revealed that introduction of Ura(Pyr) into TFOs could effectively stabilize their triplex structures without loss of base recognition capabilities.
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Seio K, Sekine M, Tago N, Masaki Y, Nagasawa H, Kanamori T, Ohkubo A. A New Microfluidic Phase-Transfer Reaction Using HPLC Guard Columns as the Reactor for the N3-Protection of Uridine Derivatives. Synlett 2015. [DOI: 10.1055/s-0035-1560358] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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32
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Tago N, Katolik A, Clark NE, Montemayor EJ, Seio K, Sekine M, Hart PJ, Damha MJ. Design, Synthesis, and Properties of Phosphoramidate 2',5'-Linked Branched RNA: Toward the Rational Design of Inhibitors of the RNA Lariat Debranching Enzyme. J Org Chem 2015; 80:10108-18. [PMID: 26378468 PMCID: PMC4749351 DOI: 10.1021/acs.joc.5b01719] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Two RNA fragments linked by means of a 2',5' phosphodiester bridge (2' hydroxyl of one fragment connected to the 5' hydroxyl of the other) constitute a class of nucleic acids known as 2'-5' branched RNAs (bRNAs). In this report we show that bRNA analogues containing 2'-5' phosphoramidate linkages (bN-RNAs) inhibit the lariat debranching enzyme, a 2',5'-phosphodiesterase that has recently been implicated in neurodegenerative diseases associated with aging. bN-RNAs were efficiently generated using automated solid-phase synthesis and suitably protected branchpoint building blocks. Two orthogonally removable groups, namely the 4-monomethoxytrityl (MMTr) group and the fluorenylmethyl-oxycarbonyl (Fmoc) groups, were evaluated as protecting groups of the 2' amino functionality. The 2'-N-Fmoc methodology was found to successfully produce bN-RNAs on solid-phase oligonucleotide synthesis. The synthesized bN-RNAs resisted hydrolysis by the lariat debranching enzyme (Dbr1) and, in addition, were shown to attenuate the Dbr1-mediated hydrolysis of native bRNA.
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Seio K, Sekine M, Tago N, Masaki Y, Nagasawa H, Kanamori T, Ohkubo A. A New Microfluidic Phase-Transfer Reaction Using HPLC Guard Columns as the Reactor for the N3-Protection of Uridine Derivatives. Synlett 2015. [DOI: 10.1055/s-0035-1560264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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34
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Yamada T, Masaki Y, Okaniwa N, Kanamori T, Ohkubo A, Tsunoda H, Seio K, Sekine M. Synthesis and properties of oligonucleotides modified with 2'-O-(2-carboxyethyl)nucleotides and their carbamoyl derivatives. Org Biomol Chem 2015; 12:6457-64. [PMID: 25019462 DOI: 10.1039/c4ob01260g] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
2'-O-Methyl oligoribonucleotides with four kinds of 2'-O-modified uridine derivatives were synthesised. Their duplex stability, hydration behavior and exonuclease resistance were studied by spectroscopic analyses and molecular dynamics simulations. Consequently, 2'-O-modification of the uridine residue with 2-carbamoylethyl or 2-(N-methylcarbamoyl)ethyl groups resulted in a significant improvement of the exonuclease resistance without the loss of duplex stability.
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Ohkubo A, Yamada K, Ito Y, Yoshimura K, Miyauchi K, Kanamori T, Masaki Y, Seio K, Yuasa H, Sekine M. Synthesis and triplex-forming properties of oligonucleotides capable of recognizing corresponding DNA duplexes containing four base pairs. Nucleic Acids Res 2015; 43:5675-86. [PMID: 26013815 PMCID: PMC4499124 DOI: 10.1093/nar/gkv496] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 05/03/2015] [Indexed: 11/28/2022] Open
Abstract
A triplex-forming oligonucleotide (TFO) could be a useful molecular tool for gene therapy and specific gene modification. However, unmodified TFOs have two serious drawbacks: low binding affinities and high sequence-dependencies. In this paper, we propose a new strategy that uses a new set of modified nucleobases for four-base recognition of TFOs, and thereby overcome these two drawbacks. TFOs containing a 2’-deoxy-4N-(2-guanidoethyl)-5-methylcytidine (dgC) residue for a C-G base pair have higher binding and base recognition abilities than those containing 2’-OMe-4N-(2-guanidoethyl)-5-methylcytidine (2’-OMegC), 2’-OMe-4N-(2-guanidoethyl)-5-methyl-2-thiocytidine (2’-OMegCs), dgC and 4S-(2-guanidoethyl)-4-thiothymidine (gsT). Further, we observed that N-acetyl-2,7-diamino-1,8-naphtyridine (DANac) has a higher binding and base recognition abilities for a T-A base pair compared with that of dG and the other DNA derivatives. On the basis of this knowledge, we successfully synthesized a fully modified TFO containing DANac, dgC, 2’-OMe-2-thiothymidine (2’-OMesT) and 2’-OMe-8-thioxoadenosine (2’-OMesA) with high binding and base recognition abilities. To the best of our knowledge, this is the first report in which a fully modified TFO accurately recognizes a complementary DNA duplex having a mixed sequence under neutral conditions.
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Tomori T, Miyatake Y, Sato Y, Kanamori T, Masaki Y, Ohkubo A, Sekine M, Seio K. Synthesis of peptide nucleic acids containing pyridazine derivatives as cytosine and thymine analogs, and their duplexes with complementary oligodeoxynucleotides. Org Lett 2015; 17:1609-12. [PMID: 25753827 DOI: 10.1021/acs.orglett.5b00522] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Synthesis of peptide nucleic acids (PNAs) is reported with new pyridazine-type nucleobases: 3-aminopyridazine (aPz) and 1-aminophthalazine (aPh) as cytosine analogs, and pyridazin-3-one (Pz(O)) and phthalazin-1-one (Ph(O)) as thymine analogs. The PNAs having an aPz or a Pz(O) formed duplexes with each complementary oligodeoxynucleotide forming a base pair with G or A, respectively, as evaluated by using UV melting analyses and circular dichroism (CD) spectra.
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Tokugawa M, Kaneko K, Saito M, Kanamori T, Masaki Y, Ohkubo A, Sekine M, Seio K. Synthesis of Responsive Fluorescent Nucleobases 7-(Benzofuran-2-yl)-7-deazahypoxanthine and 7-(Benzofuran-2-yl)-7-deazaguanine Using Cross-coupling Reaction. CHEM LETT 2015. [DOI: 10.1246/cl.140879] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Masaki Y, Inde T, Nagata T, Tanihata J, Kanamori T, Seio K, Takeda S, Sekine M. Enhancement of exon skipping in mdx52 mice by 2′-O-methyl-2-thioribothymidine incorporation into phosphorothioate oligonucleotides. MEDCHEMCOMM 2015. [DOI: 10.1039/c4md00468j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Incorporation of 2′-O-methyl-2-thioribothymidine (s2Tm) into antisense oligoribonucleotides significantly enhanced the exon skipping activity in Duchenne muscular dystrophy model mice.
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Kanamori T, Ohzeki H, Masaki Y, Ohkubo A, Takahashi M, Tsuda K, Ito T, Shirouzu M, Kuwasako K, Muto Y, Sekine M, Seio K. Controlling the fluorescence of benzofuran-modified uracil residues in oligonucleotides by triple-helix formation. Chembiochem 2014; 16:167-76. [PMID: 25469677 DOI: 10.1002/cbic.201402346] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Indexed: 12/16/2022]
Abstract
We developed fluorescent turn-on probes containing a fluorescent nucleoside, 5-(benzofuran-2-yl)deoxyuridine (dU(BF)) or 5-(3-methylbenzofuran-2-yl)deoxyuridine (dU(MBF)), for the detection of single-stranded DNA or RNA by utilizing DNA triplex formation. Fluorescence measurements revealed that the probe containing dU(MBF) achieved superior fluorescence enhancement than that containing dU(BF). NMR and fluorescence analyses indicated that the fluorescence intensity increased upon triplex formation partly as a consequence of a conformational change at the bond between the 3-methylbenzofuran and uracil rings. In addition, it is suggested that the microenvironment around the 3-methylbenzofuran ring contributed to the fluorescence enhancement. Further, we developed a method for detecting RNA by rolling circular amplification in combination with triplex-induced fluorescence enhancement of the oligonucleotide probe containing dU(MBF).
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Yamada K, Masaki Y, Tsunoda H, Ohkubo A, Seio K, Sekine M. A new modified cytosine base capable of base pairing with guanine using four hydrogen bonds. Org Biomol Chem 2014; 12:2255-62. [PMID: 24569493 DOI: 10.1039/c3ob42420k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Oligonucleotides, containing 4-N-(1H-pyrrol-2-ylcarbonyl)deoxycytidine (dC(Pyc)) and related derivatives, were synthesized via deprotection using 1.5 M NaOMe/MeOH. Among them, oligodeoxynucleotides containing dC(Pyc) exhibited a higher hybridization affinity for DNA and RNA than the unmodified oligodeoxynucleotides. Comparative analysis between dC(Pyc) and its derivatives by molecular dynamic simulation indicated that the C(Pyc) residue could form four hydrogen bonds with the opposite G nucleobase keeping a more planar structure than the C(Inc) residue where the Pyc group was replaced with a 1H-indol-2-ylcarbonyl group.
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Seio K, Kanamori T, Sekine M. Synthesis of branched DNA using oxidatively cleavable tritylsulfenyl as a hydroxy protecting group. CURRENT PROTOCOLS IN NUCLEIC ACID CHEMISTRY 2014; 58:2.18.1-2.18.19. [PMID: 25199636 DOI: 10.1002/0471142700.nc0218s58] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The application of oxidatively cleavable tritylsulfenyl (TrS) group to the synthesis of branched DNA is described. The TrS protecting group can be removed by treatment with 1 M aqueous iodine, while it is stable toward an oxaziridine-type oxidant. At the same time, the sulfur-oxygen linkage showed sufficient stability under the acidic and basic conditions used in oligonucleotide synthesis. These properties of the TrS group enabled the synthesis of branched DNA using a branched phosphoramidite in which the two hydroxy groups are protected by a 4,4'-dimethoxytrityl (DMTr) group or a TrS group. In this unit, we describe an example of the synthesis of a three-way branched DNA using a branched phosphoramidite.
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Masaki Y, Miyasaka R, Hirai K, Kanamori T, Tsunoda H, Ohkubo A, Seio K, Sekine M. Properties of 5- and/or 2-modified 2′-O-cyanoethyl uridine residue: 2′-O-cyanoethyl-5-propynyl-2-thiouridine as an efficient duplex stabilizing component. Org Biomol Chem 2014; 12:1157-62. [DOI: 10.1039/c3ob41983e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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43
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Ohkubo A, Seio K, Sekine M. Development of New Methods for Synthesis of Artificial Nucleic Acids having Various Functional Groups. J SYN ORG CHEM JPN 2014. [DOI: 10.5059/yukigoseikyokaishi.72.899] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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44
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Iijima Y, Kojima S, Kodama E, Kurohagi S, Kanamori T, Masaki Y, Ohkubo A, Sekine M, Seio K. Modified oligodeoxynucleotide primers for reverse-transcription of target RNAs that can discriminate among length variants at the 3'-terminus. Org Biomol Chem 2013; 11:8276-82. [PMID: 24173562 DOI: 10.1039/c3ob41901k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
To discriminate among miRNA length variants, we synthesized conformationally restricted or unrestricted oligonucleotides containing a cyclohexyl phosphate residue. These oligonucleotides formed duplexes with length-matched complementary miRNAs more tightly than with length variants. The use of one of these modified oligodeoxynucleotides as a reverse transcription primer enabled a novel RT-PCR that can discriminate among miRNA length variants.
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Seio K, Tokugawa M, Tsunoda H, Ohkubo A, Arisaka F, Sekine M. Assembly of pyrene-modified DNA/RNA duplexes incorporating a G-rich single strand region. Bioorg Med Chem Lett 2013; 23:6822-4. [PMID: 24183539 DOI: 10.1016/j.bmcl.2013.10.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 10/02/2013] [Accepted: 10/05/2013] [Indexed: 01/04/2023]
Abstract
The structural properties of a DNA/RNA duplex having a pyrene residue at the 5' end of DNA and a G-rich single strand region at the 3' end of RNA were studied in detail. Fluorescence and ultracentrifugation analyses indicated the formation of a complex containing four DNA/RNA duplexes, which required a pyrene residue, G-rich sequence, RNA-type backbone, and high salt concentration.
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Ohkubo A, Kondo Y, Suzuki M, Kobayashi H, Kanamori T, Masaki Y, Seio K, Nagai K, Sekine M. Chemical synthesis of U1 snRNA derivatives. Org Lett 2013; 15:4386-9. [PMID: 23952175 PMCID: PMC3901379 DOI: 10.1021/ol401917r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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U1 snRNA is an interesting biological tool for splicing correction and regulation of gene expression. However, U1 snRNA has never been chemically synthesized. In this study, the first chemical synthesis of U1snRNA and its analogues was carried out. Moreover, it was found that the binding affinity of the modified U1 snRNA with an ethylene glycol linkage to snurportin 1 (nuclear import adaptor) was as high as that of the unmodified RNA.
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Yamada K, Ohkubo A, Esaka Y, Kanamori T, Masaki Y, Seio K, Sekine M. Base recognition of gap sites in DNA–DNA and DNA–RNA duplexes by short oligonucleotides. Bioorg Med Chem Lett 2013; 23:3448-51. [DOI: 10.1016/j.bmcl.2013.03.054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 03/11/2013] [Accepted: 03/15/2013] [Indexed: 10/27/2022]
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48
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Seio K, Kanamori T, Tokugawa M, Ohzeki H, Masaki Y, Tsunoda H, Ohkubo A, Sekine M. Fluorescent properties of oligonucleotides doubly modified with an indole-fused cytosine analog and 2-aminopurine. Bioorg Med Chem 2013; 21:3197-201. [PMID: 23628471 DOI: 10.1016/j.bmc.2013.03.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 03/14/2013] [Accepted: 03/15/2013] [Indexed: 11/16/2022]
Abstract
Single- and double-stranded oligodeoxynucleotides (ODNs) incorporating both 2-aminopurine (2AP) and an indole-fused cytosine analog (PPI) were prepared and studied for their fluorescence properties. PPI and 2AP can be excited simultaneously by irradiation at 300 nm, with emission observed at 500 nm for PPI and 370 nm for 2AP. We demonstrated the utility of these properties in the dual fluorescence labeling of ODNs giving well-separated emission peaks. In addition, both of the fluorescence signals of a doubly modified ODN changed independently, reflecting the local duplex formation at the regions containing 2AP or PPI. Potential applications of this strategy for the dual fluorescence labeling of oligonucleotides with 2AP and PPI include monitoring local structure alterations of functional nucleic acids and the multiplex detection of biologically important nucleic acids.
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Yamada K, Hattori Y, Inde T, Kanamori T, Ohkubo A, Seio K, Sekine M. Remarkable stabilization of antiparallel DNA triplexes by strong stacking effects of consecutively modified nucleobases containing thiocarbonyl groups. Bioorg Med Chem Lett 2013; 23:776-8. [DOI: 10.1016/j.bmcl.2012.11.079] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 10/31/2012] [Accepted: 11/20/2012] [Indexed: 11/30/2022]
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Nojima T, Konno H, Kodera N, Seio K, Taguchi H, Yoshida M. Nano-scale alignment of proteins on a flexible DNA backbone. PLoS One 2012; 7:e52534. [PMID: 23300700 PMCID: PMC3530504 DOI: 10.1371/journal.pone.0052534] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 11/14/2012] [Indexed: 01/06/2023] Open
Abstract
Nano-scale alignment of several proteins with freedom of motion is equivalent to an enormous increase in effective local concentration of proteins and will enable otherwise impossible weak and/or cooperative associations between them or with their ligands. For this purpose, a DNA backbone made of six oligodeoxynucleotide (ODN) chains is designed in which five double-stranded segments are connected by four single-stranded flexible linkers. A desired protein with an introduced cysteine is connected covalently to the 5'-end of azido-ODN by catalyst-free click chemistry. Then, six protein-ODN conjugates are assembled with their complementary nucleotide sequences into a single multi-protein-DNA complex, and six proteins are aligned along the DNA backbone. Flexible alignment of proteins is directly observed by high-speed AFM imaging, and association of proteins with weak interaction is demonstrated by fluorescence resonance energy transfer between aligned proteins.
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