The ability of non-ionic methoxyethylphosphoramidate (PNHME) alpha-oligodeoxynucleotides (ODNs), alpha dT(15) and alpha dCT dodecamer, to form triplexes with their double-stranded DNA targets was evaluated. Thermal stability of the formed complexes was studied by UV thermal denaturation and the data showed that these PNHME alpha-ODNs formed much more stable triplexes than phosphodiester (PO) beta-ODNs did (Delta Tm = + 20 degrees C for alpha dCT PNHME). In addition, FTIR spectroscopy was used to determine the base pairing and the strand orientations of the triplexes formed by alpha dT(15) PNHME compared to phosphodiester ODNs with beta or alpha anomeric configuration. While beta dT(15) PO failed to form a triplex with a long beta dA(n) x beta dT(n) duplex, the Tm of the Hoogsteen part of the triplex formed by alpha dT(15) PNHME reached 40 degrees C. Moreover alpha dT(15) PNHME displaced the beta dT(15) strand of a shorter beta dA(15) x beta dT(15) duplex. The alpha dCT PNHME and alpha dT(15) PNHME third strands were found antiparallel in contrast to alpha dT(15) PO which is parallel to the purine strand of their duplex target. The uniform preferential Hoogsteen pairing of the nucleotides alpha dT and alpha dC combining both replacements might contribute to the improve stability of the triplexes.
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http://dx.doi.org/10.1080/07391102.2002.10506810 | DOI Listing |
Polymers (Basel)
March 2024
School of Chemical Engineering & Technology, Tianjin University, Tianjin 300350, China.
In this study, a () strain DT1 capable of producing exopolysaccharides (EPS) was isolated from dried cabbages of Tianjin, a local fermented vegetable product. Three distinct polysaccharide fractions were isolated from the fermentation broth of DT1, namely, DT1-0, DT1-2, and DT1-5. The structural composition and properties of these fractions were investigated.
View Article and Find Full Text PDFInt J Biol Macromol
October 2018
College of Marine Life Sciences, Ocean university of China, Yushan Road, No. 5, Qingdao, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, 266003 Qingdao, China. Electronic address:
A high molecular weight (Mw) pullulan has many potential applications in various fields. α-Amylase, glucoamylase and pullulanase were thought to play an important role in high Mw pullulan biosynthesis. However, there is no genetic evidence for this role.
View Article and Find Full Text PDFBiochim Biophys Acta
February 2014
Laboratory of Protein Structure, Function and Design, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address:
PriB is a basic 10-kDa protein that acts as a facilitator in PriA-dependent replication restart in Escherichia coli. PriB has an OB-fold dimer structure and exhibits single-stranded DNA (ssDNA)-binding activities similar to single-stranded binding protein (SSB). In this study, we examined PriB's interaction with ssDNA (oligo-dT35, -dT15, and -dT7) using heteronuclear NMR analysis.
View Article and Find Full Text PDFBiopolymers
November 2006
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo 2, 16610 Prague 6, Czech Republic.
A synthetic approach leading to novel-type modified oligothymidylates containing an isosteric, isopolar, enzyme-stable C3'-O-P-CH(2)-O-C4'' phosphonate alternative to phosphodiester internucleotide bond was elaborated. The suitable monomers were prepared from 4'-phosphonomethoxy derivatives of alpha-L-threo and beta-D-erythro-2',5'-dideoxythymidine, which were considered interesting as structurally related to nucleoside 5'-monophosphates. The phosphotriester method was applied to the automated synthesis of both homooligomeric phosphonate 15-mer chains and alternating phosphonate-phosphate constructs.
View Article and Find Full Text PDFJ Biomol Struct Dyn
December 2003
Laboratoire de Chimie Organique Biomoléculaire de Synthese, UMR 5625 CNRS-UMII, CC 008, Université Montpellier II, Place Eugène Bataillon, 34095 Montpellier Cedex, France.
The triplexes formed by pyrimidine alpha-oligodeoxynucleotides, 15mers alpha dT(15) or 12mers alpha dCT having dimethoxyethyl (PNHdiME), morpholino (PMOR) or propyl (PNHPr) non-ionic phosphoramidate linkages with DNA duplex targets have been investigated by UV and FTIR spectroscopy. Due to the decrease in the electrostatic repulsion between partner strands of identical lengths all modifications result in triplexes more stable than those formed with unmodified phosphodiester beta-oligodeoxynucleotides (beta-ODNs). Among the alpha-ODN third strands having C and T bases and non-ionic phosphoramidate linkages (alpha dCTPN) the most efficient modification is (PNHdiME).
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