Modified nucleotides
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Three structurally diverse types of the protected pyrrolidine nucleoside phosphonates were prepared as the monomers for the introduction of pyrrolidine nucleotide units into modified oligonucleotides on the solid phase. Two different chemistries were used for incorporation of modified and natural units: the phosphotriester method for the former, i.e., monomers containing N-phosphonoalkyl and N-phosphonoacyl moieties attached to the pyrrolidine ring nitrogen atom, and phosphoramidite chemistry for the latter. Since the synthesized pyrrolidine nucleoside phosphonic acids are close mimics of the 3'-deoxynucleoside 5'-phosphates, the incorporation of one modified unit into oligonucleotides gives rise to one 2',5' internucleotide linkage. A series of nonamers containing two or three modified units, as well as the fully modified adenine 15-mer, were synthesized in reverse order, i.e., from the 5' to the 3' end of the strand. The measurement of thermal characteristics of the complexes of modified nonamers with the complementary strand revealed a destabilizing effect of the introduced modification. The modified adenine homooligonucleotide, was found to form the most stable complex with oligothymidylate of all the tested modified oligonucleotides in terms of ?Tm per modification.
Squaramate-linked 2'-deoxycytidine 5'-O-triphosphate was synthesized and found to be good substrate for KOD XL DNA polymerase in primer extension or PCR synthesis of modified DNA. The resulting squaramate-linked DNA reacts with primary amines to form a stable diamide linkage. This reaction was used for bioconjugations of DNA with Cy5 and Lys-containing peptides. Squaramate-linked DNA formed covalent cross-links with histone proteins. This reactive nucleotide has potential for other bioconjugations of nucleic acids with amines, peptides or proteins without need of any external reagent.
- MeSH
- DNA metabolismus MeSH
- lidé MeSH
- lysin metabolismus MeSH
- nukleotidy metabolismus MeSH
- peptidy chemie MeSH
- proteiny chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The aim of this article is to study the modification of an inner capillary wall with sol-gel coating (pure silica sol-gel or silica sol-gel containing porphyrin-brucine conjugate) and determine its influence on the separation process using capillary electrophoresis/electrochromatography method. After modification of the inner capillary surface the separation of analytes was performed using two different phosphate buffers (pH 2.5 and 9.0) and finally the changes in electrophoretic mobilities of various samples were calculated. To confirm that the modification of the inner capillary surface was successful, the parts of the inner surfaces of capillaries were observed using scanning electron microscopy. The analytes used as testing samples were oligopeptides, nucleosides, nucleobases and finally nucleotides.
- MeSH
- chemické techniky analytické přístrojové vybavení metody MeSH
- kapilární elektrochromatografie * MeSH
- mikroskopie elektronová rastrovací MeSH
- nukleosidy izolace a purifikace MeSH
- nukleotidy izolace a purifikace MeSH
- oligopeptidy izolace a purifikace MeSH
- změna skupenství MeSH
- Publikační typ
- časopisecké články MeSH
Nucleosides and 2'-deoxyribonucleoside triphosphates (dNTPs) bearing phenothiazine (PT) attached to a nucleobase (cytosine or 7-deazaadenine) either directly or through an acetylene linker were prepared through Suzuki or Sonogashira cross-coupling and triphosphorylation, and were studied as building blocks for polymerase construction of modified DNA. The directly PT-substituted dNTPs were better substrates for polymerases than the alkyne-linked dNTPs but all of them were used in enzymatic synthesis of DNA using primer extension, nicking enzyme amplification, PCR or 3'-tail labelling by terminal deoxynucleotidyl transferase. The phenothiazine served as an oxidizable redox label (giving two analytically useful signals of oxidation on electrode) for nucleosides and DNA and was also used in orthogonal combination with previously developed benzofurazane or nitrophenyl labels for redox coding of DNA bases. Therefore, the title PT-linked dNTPs are useful additions to the portfolio of nucleotides for enzymatic synthesis of redox-labelled DNA for electrochemical analysis.
Our investigation in the chemistry of nucleoside phosphonates has provided an impressive number of novel structurally diverse compounds. Among them, several potent inhibitors of enzymes of nucleosides and nucleotide salvage pathways were found. The findings obtained in synthesis of nucleoside phosphonates are unique. The nucleoside phosphonates provided several types of monomers for the synthesis of modified oligonucleotides. The first non-silyl protecting group was developed and used in the solid-phase synthesis of modified oligoribonucleotides in the reverse direction. The superior nuclease stability of phosphonate internucleotide linkages, their ability to enhance hybridization together with the ability to elicit RNase H activity may classify these compounds as useful in biochemistry and biology
- MeSH
- biochemické jevy MeSH
- fosforylasy chemie metabolismus MeSH
- inhibitory enzymů chemie metabolismus MeSH
- lidé MeSH
- molekulární konformace MeSH
- nukleotidy biosyntéza chemie metabolismus MeSH
- oligonukleotidy * biosyntéza chemie metabolismus MeSH
- organofosfonáty * chemická syntéza chemie metabolismus MeSH
- ribonukleasy chemie metabolismus MeSH
- toll-like receptory chemie metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
The syntheses of 5-arylsulfanyl- or 5-arylselanylpyrimidine and 7-arylsulfanyl- or 7-arylselanyl-7-deazapurine nucleosides and nucleotides were developed by the Cu-mediated sulfanylations or selanylations of the corresponding 5-iodopyrimidine or 7-iodo-7-deazapurine nucleosides or nucleotides with diaryldisulfides or -diselenides. The reactions were also applicable for direct modifications of 2'-deoxycytidine triphosphate and the resulting 5-arylsulfanyl or 5-arylselanyl-dCTP served as substrates for the polymerase synthesis of modified DNA bearing arylsulfanyl or arylselanyl groups in the major groove.
Linear or branched 1,3-diketone-linked thymidine 5'-O-mono- and triphosphate were synthesized through CuAAC click reaction of diketone-alkynes with 5-azidomethyl-dUMP or -dUTP. The triphosphates were good substrates for KOD XL DNA polymerase in primer extension synthesis of modified DNA. The nucleotide bearing linear 3,5-dioxohexyl group (HDO) efficiently reacted with arginine-containing peptides to form stable pyrimidine-linked conjugates, whereas the branched 2-acetyl-3-oxo-butyl (PDO) group was not reactive. Reaction with Lys or a terminal amino group formed enamine adducts that were prone to hydrolysis. This reactive HDO modification in DNA was used for bioconjugations and cross-linking with Arg-containing peptides or proteins (e.g. histones).
- MeSH
- arginin chemie MeSH
- DNA chemická syntéza chemie MeSH
- histony chemie MeSH
- ketony chemická syntéza chemie MeSH
- nádorový supresorový protein p53 chemie MeSH
- peptidy chemie MeSH
- proteiny chemie MeSH
- reagencia zkříženě vázaná chemická syntéza chemie MeSH
- sérový albumin hovězí chemie MeSH
- skot MeSH
- thiminnukleotidy chemická syntéza chemie MeSH
- zvířata MeSH
- Check Tag
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Synthesis of base-modified dNTPs through the Suzuki or Sonogashira cross-coupling reactions of halogenated dNTPs with boronic acids or alkynes is reported, as well as the use of these modified dNTPs in polymerase incorporations to oligonucleotides or DNA by primer extension or PCR.
Five 2'-deoxyribonucleoside triphosphates (dNTPs) derived from epigenetic pyrimidines (5-methylcytosine, 5-hydroxymethylcytosine, 5-formylcytosine, 5-hydroxymethyluracil, and 5-formyluracil) were prepared and systematically studied as substrates for nine DNA polymerases in competition with natural dNTPs by primer extension experiments. The incorporation of these substrates was evaluated by a restriction endonucleases cleavage-based assay and by a kinetic study of single nucleotide extension. All of the modified pyrimidine dNTPs were good substrates for the studied DNA polymerases that incorporated a significant percentage of the modified nucleotides into DNA even in the presence of natural nucleotides. 5-Methylcytosine dNTP was an even better substrate for most polymerases than natural dCTP. On the other hand, 5-hydroxymethyl-2'-deoxyuridine triphosphate was not the best substrate for SPO1 DNA polymerase, which naturally synthesizes 5hmU-rich genomes of the SPO1 bacteriophage. The results shed light onto the possibility of gene silencing through recycling and random incorporation of epigenetic nucleotides and into the replication of modified bacteriophage genomes.
- MeSH
- 5-methylcytosin * MeSH
- deoxyribonukleosidy MeSH
- DNA-dependentní DNA-polymerasy metabolismus MeSH
- DNA metabolismus MeSH
- epigeneze genetická MeSH
- nukleotidy metabolismus MeSH
- pyrimidinové nukleotidy * MeSH
- pyrimidiny MeSH
- restrikční enzymy metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
