Wyniki wyszukiwania

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Cyclopentenyl cytosine inhibits CTP synthetase in pediatric acute non-lymphocytic leukemia

100%

Verschuur A. C., Van Gennip A. H., Leen R., Voute P. A., Van Kuilenburg A. B. P.

Cellular and Molecular Biology Letters

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1999

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tom 04

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nr 3

2

Methoxyamine attack on cytosine produces ambivalent base pairing properties of the modified base

75%

Gdaniec Z., Sowers L. C., Fazakerley G. V.

Acta Biochimica Polonica

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1996

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tom 43

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nr 1

We report the solution structure of two heptanucleotides each containing a central N4-methoxycytosine, in one case with adenine on the opposite strand and in the other with guanine. For the N4 -methoxycytosine-adenine pair only the imino form of the N4 -methoxycytosine residue is observed and base pairing is in Watson-Crick geometry. However, rotation of the methoxy group about the N-OCH3 bond is not constrained to a particular orientation although it must be anti to the N3 of .V,-methoxycytosine. The slow exchange on a proton NMR time scale between the single strand and double strand forms is attributed to the strong preference of the syn conformation of the OCH3 group in the single strand which inhibits base pair formation. For N4 -methoxycytosine base paired with guanosine we observe the N4 -methoxycytosine base in the amino form in Watson-Crick geometry and a slow exchange of this species with an imino form base paired in wobble geometry. The amino form is predominant at low temperature whereas the imino form predominates above 40°C. Our results point to preferential replacement of dTTP by N4 -methoxycytosine in primer elongation.

3

Enhanced nucleolar parameters in Vicia faba L. induced by 5-azacytidine may be only partly attributed to DNA demethylation

63%

Olszewska M. J., Sakowicz T., Kazmierczak J., Luchniak P.

Folia Histochemica et Cytobiologica

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1997

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tom 35

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nr 3

4

Role of epigenetic DNA alterations in the pathogenesis of systemic lupus erythematosus

63%

Januchowski R., Prokop J., Jagodzinski P. P.

Journal of Applied Genetics

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2004

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tom 45

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nr 2

5

The role of side chains in the interaction of new antitumor pyrimidoacridinetriones with DNA: molecular dynamics simulations

63%

Mazerski J., Antonini I., Martelli S.

Acta Biochimica Polonica

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2000

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tom 47

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nr 1

Pyrimidoacridinetriones (PATs) are a new group of highly active antitumor compounds. It seems reasonable to assume that, like for some other acridine derivatives, intercalation into DNA is a necessary, however not a sufficient condition for antitumor activity of these compounds. Rational design of new compounds of this chemotype requires knowledge about the structure of the intercalation complex, as well as about interactions responsible for its stability. Computer simulation techniques such as molecular dynamics (MD) may provide valuable information about these problems. The results of MD simulations performed for three rationally selected PATs are presented in this paper. The compounds differ in the number and position of side chains. Each of the compounds was simulated in two systems: i)in water, and ii) in the intercalation complex with the dodecamer duplex d(GCGCGCGCGCGC)2. The orientation of the side chain in relation to the ring system is determined by the position of its attachment. Orientation of the ring system inside the intercalation cavity depends on the number and position of side chain(s). The conformations of the side chain(s) of all PATs studied in the intercalation complex were found to be very similar to those observed in water.

6

Some kinetic studies on cytidine aminohydrolase activity from Aspergillus niger NRRL3

51%

Ali T. H.

Acta Microbiologica Polonica

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1998

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tom 47

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nr 4

7

The use of E.coli cytosine deaminase gene as an example of suicide gene therapy of cancer

51%

Missol E., Sochanik A., Szala S.

Biotechnologia

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