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1

Srodowisko, pestycydy, nowotwory

100%
Kusmierek J. T.
Wiedza i Życie
|
1994
|
nr 12
17-22
2

Alkylation of cytosine glycosides in alkaline medium: a new route to the preparation of O'-alkylated nucleosides and nucleotides of cytosine and uracil

84%
Kusmierek J. T., Shugar D.
Acta Biochimica Polonica
|
1971
|
tom 18
|
nr 4
3

Molekularne podstawy mutagennego dzialania chlorku winylu

84%
Mroczkowska-Slupska M. M., Kusmierek J. T.
Postępy Biochemii
|
1994
|
tom 40
|
nr 1
31-39
4

Hydrolysis of 5-cyano-, and decarboxylation of 5-carboxy-, uracils: a facile route to the synthesis of analogues of 1-cyclohexyluracil and cytosine

84%
Kusmierek J. T., Shugar D.
Acta Biochimica Polonica
|
1970
|
tom 17
|
nr 4
5

Alkylation of cytidine-5'-phosphate: mechanisms of alkylation, influence of O'-alkylation on susceptibility of pyrimidine nucleotides to some nucleolytic enzymes, and synthesis of 2'-O-alkyl polynucleotides

84%
Kusmierek J. T., Shugar D.
Acta Biochimica Polonica
|
1973
|
tom 20
|
nr 4
6

Miscoding properties of isoguanine [2-oxoadenine] studied in an AMV reverse transcriptase in vitro system

84%
Bukowska A. M., Kusmierek J. T.
Acta Biochimica Polonica
|
1996
|
tom 43
|
nr 1
We have found that isoguanine (¡G) can pair with thymine (iG T) and the non- natural base, 5-methylisocytosine (iG x iCM) during template directed synthesis catalyzed by AMV reverse transcriptase. The ratio of these pairings is about 1:10, irrespectively which of the templates, poly(C,iG) or poly(I,iG) is used. This ratio corresponds to the ratio of 2-OH and 2-keto tautomers in monomer in aqueous sol ution and apparently it is not influenced by the template context. Our results indicate also that formation of the reverse transcriptase catalyzed base pairs between iG and A, G or C can occur only at a low frequency, comparable to the frequency, of mismatches of.
7

Template-directed base pairing of 2-chloro-2'-deoxyadenosine catalyzed by AMV reverse transcriptase

84%
Bukowska-Maciejewska A. M., Kusmierek J. T.
Acta Biochimica Polonica
|
1998
|
tom 45
|
nr 2
2-Chloro-2'-deoxyadenine (2CldA) is used for treatment of several lymphoid malignancies. Since this drug is incorporated into DNA, we have undertaken studies on base pairing of 2-chloroadenine (2ClA). 2CldA phosphoramidite was synthesized and used for preparation of 25-mer templates with 2ClA located at site 21 from the 3'-end. Kinetic parameters (Km and Vmax) for the incorporation of deoxynucleoside-5'-triphosphates by AMV reverse transcriptase opposite the 2ClA template, as well as for the extension of 2ClA·T pair, were determined. The efficiency (Vmax/Km) of incorporation of dGTP, dCTP, and dATP opposite 2ClA is at least one order of magnitude lower than opposite unmodified A. The efficiency of incorporation of dTTP opposite 2ClA is about 30-fold lower than opposite A and extension of 2ClA·T pair is 3-fold lower than of A·T pair. From the analysis of the parameters of dTTP incorporation we conclude that formation of 2ClA·T pair is thermodynamically, but not kinetically controlled. The difference in binding energy (ΔΔG) between 2ClA·T and A·T pairs in the environment of the polymerase active site is 2 kcal/mol. Our results indicate that the presence of 2ClA in DNA slows down replication, but does not lead to base-substitution mutations.
8

Endogenous and exogenous DNA lesions recognized by N-alkylpurine-DNA glycosylases

84%
Borys E., Kusmierek J. T.
Acta Biochimica Polonica
|
1998
|
tom 45
|
nr 2
The combined action of glycosylases and abasic site-specific endonucleases on damaged bases in DNA results in single strand breaks.In plasmid DNA, as a consequence, the covalently closed circular (ccc) form is converted to the open circular (oc) form, and this can be quantitated by agarose gel electrophoresis. We studied DNA lesions sensitive to E. coli 3-methyladenine-DNA glycosylase II (AlkA) and cloned human N-alkylpurine-DNA glycosylase (ANPG-40) which are known to excise alkylated bases and etheno adducts. pBR322 and pAlk10 plasmids not pretreated with mutagens were cleaved by both glycosylases in the presence of enzymes possessing endonucleolytic activity, which indicates that plasmids contain unknown, endogenously formed adducts. Plasmids pretreated with chloroacetaldehyde, a mutagen forming etheno adducts, exhibited enhanced sensitivity to both glycosylases. Adducts formed by acrolein and croton aldehyde were excised by AlkA, but not by ANPG-40, whereas malondialdehyde adducts were not excised by either glycosylase. Bulky p-benzochinone adducts were not excised by AlkA, however, the plasmid pretreated with this mutagen was incised by endonucleases, possibly without prior generation of an abasic site. These examples show that examination of conformational changes of plasmid DNA can be taken advantage of to study the specificity of N-alkylpurine-DNA-glycosylases.
9

Bacterial DNA repair genes and their eukaryotic homologues: 2. Role of bacterial mutator gene homologues in human disease. Overview of nucleotide pool sanitization and mismatch repair system

84%
Arczewska K. D., Kusmierek J. T.
Acta Biochimica Polonica
|
2007
|
tom 54
|
nr 3
Since the discovery of the first E. coli mutator gene, mutT, most of the mutations inducing elevated spontaneous mutation rates could be clearly attributed to defects in DNA repair. MutT turned out to be a pyrophosphohydrolase hydrolyzing 8-oxodGTP, thus preventing its incorporation into DNA and suppresing the occurrence of spontaneous AT→CG transversions. Most of the bacterial mutator genes appeared to be evolutionarily conserved, and scientists were continuously searching for contribution of DNA repair deficiency in human diseases, especially carcinogenesis. Yet a human MutT homologue - hMTH1 protein - was found to be overexpressed rather than inactivated in many human diseases, including cancer. The interest in DNA repair contribution to human diseases exploded with the observation that germline mutations in mismatch repair (MMR) genes predispose to hereditary non-polyposis colorectal cancer (HNPCC). Despite our continuously growing knowledge about DNA repair we still do not fully understand how the mutator phenotype contributes to specific forms of human diseases.
10

Practical highly enantioselective synthesis of [R]- and [S]-[E]-4-hydroxynon-2-enal

68%
Komisarski M., Kaczmarska Z., Kusmierek J. T.
Acta Biochimica Polonica
|
2009
|
tom 56
|
nr 1
189-193
 Oxidative stress enhances lipid peroxidation (LPO) implicated in cancer promotion and progression. (E)-4-Hydroxynon-2-enal 1 (trans-4-hydroxy-2-nonenal, HNE) is one of the most abundant products of LPO. Reactions of HNE with DNA and proteins are responsible for its mutagenic and toxic effects. On the other hand, HNE is regarded as a key molecule in stress mediated cell cycle signaling. LPO generates racemic HNE (rac-1); however, it is expected that the individual enantiomers will behave differently in their interactions with cell components. The study of HNE stereochemistry in its chemical and biochemical interactions is hindered by the lack of expedient methods for preparation of pure enantiomers. This study presents one step synthesis of HNE in a cross-metathesis reaction between the commercially available oct-1-en-3-ol and acrolein in the presence of 2nd generation Grubbs catalyst. The use in the metathesis reaction of enantiomers of oct-1-en-3-ol obtained via Candida antarctica lipase resolution of the racemate allowed us to prepare of 4-(R)- and 4-(S)-enantiomers of HNE (R-1 and S-1, respectively) with excellent optical purity (97.5 and 98.4% ee, respectively) and good chemical yields (70%).
11

Mismatch dependent uracil-thymine-DNA glycosylases excise exocyclic hydroxyethano and hydroxypropano cytosine adducts

51%
Borys-Brzywczy E., Arczewska K. D., Saparbaev M., Hardeland U., Schar P., Kusmierek J. T.
Acta Biochimica Polonica
|
2005
|
tom 52
|
nr 1
Exocyclic adducts of DNA bases, such as etheno- and hydroxyalkano- ones, are generated by a variety of bifunctional agents, including endogenously formed products of lipid peroxidation. In this work we selectively modified cytosines in the 5’-d(TTT TTT CTT TTT CTT TTT CTT TTT T)-3’ oligonucleotide using: chloroacetaldehyde to obtain 3,N4-α-hydroxyethano- (HEC) and 3,N4-etheno- (epsilonC), acrolein to obtain 3,N4-α-hydroxypropano- (HPC) and crotonaldehyde to obtain 3,N4αhydroxy-γ-methylpropano- (mHPC) adducts of cytosine. The studied adducts are alkali-labile which results in oligonucleotide strain breaks at the sites of modification upon strong base treatment. The oligonucleotides carrying adducted cytosines were studied as substrates of Escherichia coli Mug, human TDG and fission yeast Thp1p glycosylases. All the adducts studied are excised by bacterial Mug although with various efficiency: εC > HEC > HPC > mHPC. The yeast enzyme excises efficiently εC≥HEC>HPC, whereas the human enzyme excises only εC. The pH-dependence curves of excision of εC, HEC and HPC by Mug are bell shaped and the most efficient excision of adducts occurs within the pH range of 8.6–9.6. The observed increase of excision of HEC and HPC above pH 7.2 can be explained by deprotonation of these adducts, which are high pKa compounds and exist in a protonated form at neutrality. On the other hand, since εC is in a neutral form in the pH range studied, we postulate an involvement of an additional catalytic factor. We hypothesize that the enzyme structure undergoes a pH-induced rearrangement allowing the participation of Lys68 of Mug in catalysis via a hydrogen bond interaction of its ε-amino group with N4 of the cytosine exocyclic adducts.
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