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Equilibrium studies on the uptake of nitrate and phosphate ions using functionalized carbon cloth. J Radioanal Nucl Chem 2021. [DOI: 10.1007/s10967-021-07872-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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2
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Eichler DR, Papadantonakis GA. Activation barriers for methylation of DNA bases by dimethyl sulfate. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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3
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Rajcsanyi PM, Csillag M, Kriskovics E. Separation of Nucleic Acid Constituents by Column Liquid Chromatography. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/03602547408068431] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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4
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Golankiewicz B, Ostrowski T, Folkman W. Chemical synthesis and spontaneous glycosidic hydrolysis of 3-methyl-2'-deoxyguanosine and 2'-deoxywyosine [1]. Nucleic Acids Res 1990; 18:4779-82. [PMID: 2395642 PMCID: PMC331943 DOI: 10.1093/nar/18.16.4779] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
3-methyl-2'-deoxyguanosine (1a) is obtained from 2'-deoxyguanosine by a reaction sequence involving conversion into tricyclic 1,N-2-isopropeno derivative (4-desmethyl-2'-deoxywyosine, 3a) followed by methylation which results in 2'-deoxywyosine (2a) and final removal of the 1,N-2 blocking system. Compounds 1a and 2a undergo spontaneous hydrolytic cleavage of their glycosidic bonds at pH 7, 37 degrees C, which makes them the most labile of all known nucleosides composed of structural units occurring in nature.
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Affiliation(s)
- B Golankiewicz
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan
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Nagata C, Aida M. Ab initio molecular orbital study on the pairing and stacking interactions between nucleic acid bases in relation to the biological activities. ACTA ACUST UNITED AC 1988. [DOI: 10.1016/0166-1280(88)80141-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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6
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Sakumi K, Nakabeppu Y, Yamamoto Y, Kawabata S, Iwanaga S, Sekiguchi M. Purification and structure of 3-methyladenine-DNA glycosylase I of Escherichia coli. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(18)66783-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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7
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Briscoe WT, Cotter LE. DNA sequence has an effect on the extent and kinds of alkylation of DNA by a potent carcinogen. Chem Biol Interact 1985; 56:321-31. [PMID: 4075454 DOI: 10.1016/0009-2797(85)90014-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A system has been developed to study the effects of base sequence (neighboring bases) upon the alkylation of guanine (G) and adenine (A) bases in DNA. The study was performed on the synthetic polydeoxyribonucleotides, poly(dG).poly(dC), poly(dG-dC).poly(dG-dC), poly(dA).poly(dT), poly(dA-dT).poly(dA-dT), poly(dA-dC).poly(dG-dT), poly(dA-dG).poly(dC-dT), as well as calf thymus DNA. Each polynucleotide was treated with N-[3H]methyl-N-nitrosourea (MNU), depurinated, and the freed alkylpurines separated by HPLC and quantitated by liquid scintillation counting. The amounts of 3-methylguanine (3-MG), 7-MG, and O6-MG relative to guanine, and 3-methyladenine (3-MA) and 1-MA plus 7-MA relative to adenine, and also the O6-MG/7-MG ratios were highly reproducible for a given polynucleotide. Significant differences were found in the amounts of each of the methylpurines formed when compared among the six synthetic polynucleotides and DNA. This evidence is interpreted as an effect upon alkylation which is ultimately dependent upon the base sequence. These findings may have significance in defining the specificity of chemical carcinogens in terms of the susceptability to modification of nucleotide sequences such as those found in certain oncogenes.
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Briscoe WT, Cotter LE. The effects of neighboring bases on N-methyl-N-nitrosourea alkylation of DNA. Chem Biol Interact 1984; 52:103-10. [PMID: 6499077 DOI: 10.1016/0009-2797(84)90086-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Calf thymus DNA and the synthetic polynucleotides of defined sequence, poly(dG).poly(dC) and poly(dG-dC).poly(dG-dC) were reacted with N-methyl-N-nitrosourea (MNU) and the amounts of 7-methylguanine (7-MG) and O6-methylguanine (O6-MG) determined. It was found that the O6-MG/7-MG ratio for DNA was 0.13, for poly(dG).poly(dC) was 0.10, and for poly(dG-dC).poly(dG-dC) was 0.21. From these data, it is evident that the neighboring bases affect the alkylation pattern of guanine by MNU, a finding that can have significant relevance in defining 'hot spots' of alkylation in the genome which may be important in the processes of mutagenesis and carcinogenesis.
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Abstract
Ethyl methanesulfonate (EMS) is a monofunctional ethylating agent that has been found to be mutagenic in a wide variety of genetic test systems from viruses to mammals. It has also been shown to be carcinogenic in mammals. Alkylation of cellular, nucleophilic sites by EMS occurs via a mixed SN1/SN2 reaction mechanism. While ethylation of DNA occurs principally at nitrogen positions in the bases, because of the partial SN1 character of the reaction, EMS is also able to produce significant levels of alkylation at oxygens such as the O6 of guanine and in the DNA phosphate groups. Genetic data obtained using microorganisms suggest that EMS may produce both GC to AT and AT to GC transition mutations. There is also some evidence that EMS can cause base-pair insertions or deletions as well as more extensive intragenic deletions. In higher organisms, there is clear-cut evidence that EMS is able to break chromosomes, although the mechanisms involved are not well understood. An often cited hypothesis is that DNA bases ethylated by EMS (mostly the N-7 position of guanine) gradually hydrolyze from the deoxyribose on the DNA backbone leaving behind an apurinic (or possibly an apyrimidinic) site that is unstable and can lead to single-strand breakage of the DNA. Data also exist that suggest that ethylation of some chromosomal proteins in mouse spermatids by EMS may be an important factor in causing chromosome breakage.
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10
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Ather A, Ahmed Z, Riazuddin S. Adaptive response of Micrococcus luteus to alkylating chemicals. Nucleic Acids Res 1984; 12:2111-26. [PMID: 6701095 PMCID: PMC318644 DOI: 10.1093/nar/12.4.2111] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Wild type M. luteus cells have been adapted by a step-wise treatment with sub-lethal concentrations of MNNG. The adapted cells exhibit 5.7 fold increased resistance to the killing effects of the mutagen and a simultaneous efficient removal of various base modifications present in cellular DNA. A protein extract prepared from adapted cells contains inducible repair functions which can reduce 80-90% of the alkylated DNA content of 06-MeG is effected by a transmethylase and there is no concomitant release of the modified base. However, N-3 MeG is released as a free modified base through the action of a DNA glycosylase. The release of N-3 MeA is unaffected by the induction treatment whereas that of N-7 methylpurine is slightly improved in the adapted cells.
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Heflich RH, Beranek DT, Kodell RL, Morris SM. Induction of mutations and sister-chromatid exchanges in Chinese hamster ovary cells by ethylating agents. Mutat Res 1982; 106:147-61. [PMID: 6891748 DOI: 10.1016/0027-5107(82)90198-1] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Chinese hamster ovary (CHO) cells were exposed to [3H]ethyl nitrosourea (ENU) or [3H]ethyl methanesulfonate (EMS) and the following DNA ethylation products were quantitated: 3- and 7-ethyladenine, O2-ethylcytosine, 3-, 7- and O6-ethylguanine, O2- and O4-ethyldeoxythymidine and the representative ethylated phosphodiester, deoxythymidylyl (3'-5')ethyl-deoxythymidine. When mutations at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus induced by these same treatments were compared with the observed ethylation products, mutations were found to correlate best with 3- and O6-ethylguanine. EMS induced approximately twice as many sister-chromatid exchanges (SCEs) as ENU at doses yielding equal mutation frequencies. When SCEs were indirectly compared with DNA ethylation products, 3-ethyladenine and ethylated phosphodiesters related best to SCE formation. Because mutation and SCE induction appear, at least in part, to be related to different DNA adducts, SCE induction by simple ethylating agents may not be a quantitative indicator of potentially mutagenic DNA damage.
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Nagata C, Takeda E, Aida M. Why O6-alkylguanine is specifically promutagenic? Ab initio molecular orbital consideration. Mutat Res 1982; 105:1-8. [PMID: 7121477 DOI: 10.1016/0165-7992(82)90199-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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13
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Weaver J, Tomasz M. Reactivity of mitomycin C with synthetic polyribonucleotides containing guanine or guanine analogs. BIOCHIMICA ET BIOPHYSICA ACTA 1982; 697:252-4. [PMID: 6809051 DOI: 10.1016/0167-4781(82)90084-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The guanine residues in nucleic acids are believed to be the major covalent binding site of the antibiotic mitomycin C. To identify the specific functional group in guanine which reacts with mitomycin C, reactions were run between the antibiotic and poly(G) analogs in which guanine was blocked at the N-7 or O-6 position, or lacked the 2-amino group. Binding ratios were affected to a small extent in the two former cases, but binding was significantly decreased in the absence of the 2-amino group. These results indicate that the most likely binding site of mitomycin C in synthetic polyribonucleotides is the 2-amino group of guanine residues.
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Karran P, Hjelmgren T, Lindahl T. Induction of a DNA glycosylase for N-methylated purines is part of the adaptive response to alkylating agents. Nature 1982; 296:770-3. [PMID: 7040983 DOI: 10.1038/296770a0] [Citation(s) in RCA: 213] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Süssmuth R. Induction of prophage and mutagenic effects by alkyl alkylaminosulfonates, ethyl aminosulfonate and alkyl methanesulfonates. Mutat Res 1980; 78:301-15. [PMID: 6255325 DOI: 10.1016/0165-1218(80)90035-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Prophage induction and mutation by alkylaminosulfonates, ethyl aminosulfonate and alkyl methanesulfonates were examined comparatively. Prophage induction was carried out with a lysozyme lysis technique on the lysogenic strain Micrococcus lysodeikticus 53-40 (N5). The sulfonic ester derivatives show a slight lysogenic induction. At higher concentrations their toxicity seems to mask phage detection. Only methyl isopropylaminosulfonate and ethyl aminosulfonate exhibit no or negligible toxic effects, and with these compounds at higher concentrations a strong prophage induction is found. Alkyl sulfonate derivatives induce mutations in the tester strain of Salmonella typhimurium TA1535. Methyl methylaminosulfonate and ethyl N-methyl-N-2-chloroethyl aminosulfonate show a mutagenicity comparable to that of the well-known methyl methanesulfonate or ethyl methanesulfonate. With ethyl aminosulfonate, however, which does not show inactivation, no significant mutagenic effect was observed. DNA alterations were found in the polymerase-deficient strain E. coli P3478. The results of prophage induction and mutagenicity are compared and discussed.
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Ornstein RL, Rein R. Molecular models of induced DNA premutational damage and mutational pathways for the carcinogen 4-nitroquinoline 1-oxide and its metabolites. Chem Biol Interact 1980; 30:87-103. [PMID: 6769596 DOI: 10.1016/0009-2797(80)90117-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The carcinogen 4-nitroquinoline 1-oxide (4NQO) and its metabolites undergo intercalative or covalent binding with DNA. Recent evidence indicates that the latter binding pattern is probably facilitated by an initial weaker intercalative interaction that can align potentially reactive sites on a 4NQO-metabolite and adjacent stacked bases. In the present study, we have proposed numerous possible covalent reaction products between 4NQO and its metabolites with DNA mini-helices based on chemical properties and key 'short-contacts' after energy-minimization in 21 different intercalative-like complexes. It is known from numerous experimental studies that 90% of the quinoline-bound DNAs in vivo involve guanine with the remaining 10% apparently involving adenine residues. The results of the present study suggest that this trend is not due to the greater affinity of the quinolines for guanine, but instead results from secondary processes involving the preferential formation of apurinic sites at aralkyl-adenine residues over that of aralkyl-guanine residues. In addition, observed mutational patterns can be rationalized in terms of the proposed reaction-products. The role of DNA repair mechanisms in the removal and correction of the different proposed reaction products are discussed. The binding pattern of several other aromatic carcinogens are similar to those depicted in the present work for the 4NQO-metabolites; hence the present study may be of some general significance.
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Abstract
DMS and DES are monofunctional alkylating agents that have been shown to induce mutations, chromosomal aberrations, and other genetic alterations in a diversity of organisms. They have also been shown to be carcinogenic in animals. As an alkylating agent, DMS is a typical SN2 agent, attacking predominantly nitrogen sites in nucleic acids. DES is capable of SN1 alkylations as well as SN2 and thereby causes some alkylation on oxygen sites including the O6-position of guanine which is thought to be significant in mutagenesis by direct mispairing. The mutagenicity of DMS is better explained in terms of indirect, repair-dependent processes. With respect to both alkylating activity and genetic effects, striking similarities are found between DMS and MMS and between DES and EMS. In most systems where they have been tested, both DMS and DES are mutagenic. Results of many of the mutagenesis studies involving these compounds and other alkylating sulfuric acid esters are summarized in Tables 6, 7, 8, 9 and 10 of this review. Most data are consistent with these agents acting primarily as base-pair substitution mutagens. In the case of DES, strong specificity for G.C to A.T transitions has been reported in some systems but has not been clearly supported in some others. Low levels of frameshift mutations of the deletion type are also likely. In addition to the induction of mutations, recombinogenic and clastogenic effects have been described.
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20
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Fong LY, Lin HJ, Lee CL. Methylation of DNA in target and non-target organs of the rat with methylbenzylnitrosamine and dimethylnitrosamine. Int J Cancer 1979; 23:679-82. [PMID: 457309 DOI: 10.1002/ijc.2910230514] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The sites of labelling of DNA with [14C]methyl groups from methylbenzylnitrosamine and dimethylnitrosamine were studied in rat oesophageal epithelium and liver. All four combinations of tissue and carcinogen were studied. Tissues were labelled in vitro and the DNA contained therein purified and hydrolysed (pH 1, 37 degrees C) to free purines and apurinic acid. Quantitative analysis was performed with the aid of thin-layer chromatography. The apurinic acid and 7-methylguanine fractions were found to be extensively labelled. Smaller amounts of radioactivity were found in O6-methylguanine and some of the methylated adenines. The same carcinogen produced different patterns of labelling is oesophageal and liver DNA. The proportion of O6-methylguanine to 7-methylguanine was higher when the methylating agent was a carcinogen specific for the organ.
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Abbott PJ, Saffhill R. DNA synthesis with methylated poly(dC-dG) templates. Evidence for a competitive nature to miscoding by O(6)-methylguanine. BIOCHIMICA ET BIOPHYSICA ACTA 1979; 562:51-61. [PMID: 373805 DOI: 10.1016/0005-2787(79)90125-4] [Citation(s) in RCA: 198] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The alternating copolymer poly(dC-dG) has been methylated with either dimethyl sulphate or N-methyl-N-nitrosourea and the levels of the various methylation products determined. In addition to the 3-methylcytosine, 3-methylguanine and 7-methylguanine (produced by both agents) reaction with N-methyl-N-nitrosourea also yielded easily detectable amounts of O(6)-methylguanine and phosphotriesters. These methylated polymers were then used as templates in an in vitro assay with Escherichia coli DNA polymerase I measuring the incorporation of complementary (dCMP and dGMP) and noncomplementary (dAMP and dTMP) nucleotides. When the dimethyl sulphate-methylated polymer was used as template there was virtually no detectable incorporation of non-complementary nucleotides indicating that no miscoding could be attributed to the presence of 3-methylcytosine, 3-methylguanine or 7-methylguanine. However, when the N-methyl-N-nitrosourea-methylated polymer was used as template there was a specific incorporation of dTMP but not of dAMP. The amount of dTMP incorporated was always less than the level of O(6)-methylguanine in the template and was found to vary with the relative concentrations of the deoxynucleoside 5'-triphosphates in the assay. As the amount of dCTP present in the assay was decreased the wrong incorporation of dTMP increased and approached the level that would have been expected for a one-to-one miscoding by O(6)-methylguanine as the concentration of dCTP approached zero. The results indicate that O(6)-methylguanine is capable of miscoding with a DNA polymerase but the miscoding is competitive with the normal incorporation of dCMP: when the 5'-triphosphate precursors are present in equal amounts approximately one O(6)-methylguanine in three miscodes leading to the incorporation of dTMP.
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Shackleton J, Roberts JJ. Repair of alkylated DNA in Chinese hamster cells measured by loss of enzyme-sensitive sites in isolated DNA. Biochem Biophys Res Commun 1978; 81:1168-74. [PMID: 666813 DOI: 10.1016/0006-291x(78)91259-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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The Repair of DNA Modified by Cytotoxic, Mutagenic, and Carcinogenic Chemicals. ACTA ACUST UNITED AC 1978. [DOI: 10.1016/b978-0-12-035407-8.50012-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
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Smith BJ. Alkylation of cytosine and 5-hydroxymethyl-cytosine by methyl methanesulphonate and N-methyl-N-nitrosourea: its relevance to mutagenesis. Chem Biol Interact 1977; 16:275-80. [PMID: 193650 DOI: 10.1016/0009-2797(77)90107-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The reaction of cytosine and 5-hydroxymethyl-cytosine (OHMeCyt) with a variety of monofunctional alkylating agents has been investigated to evaluate further the possible role of cytosine alkylation in mutagenesis and the possibility that the immunity of T-even phages to mutation by methyl methanesulphonate (MMS) was due to the unreactivity of OHMeCyt towards this agent. Both cytosine and OHMeCyt reacted equally well with the methylating agents MMS and N-methyl-N-nitrosourea (MNU) affording 6% and less than 1% respectively of the 3-substituted derivative. No product was isolated following subjection of the bases to reaction with ethyl methane-sulphonate (EMS), N-ethyl-N-nitrosourea (ENU) or iso-propyl methane-sulphonate (iPMS).
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Pegg AE. Formation and metabolism of alkylated nucleosides: possible role in carcinogenesis by nitroso compounds and alkylating agents. Adv Cancer Res 1977; 25:195-269. [PMID: 326002 DOI: 10.1016/s0065-230x(08)60635-1] [Citation(s) in RCA: 247] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Ord MJ. The interaction of nuclear and cytoplasmic damage after treatments with toxic chemicals. J Theor Biol 1976; 62:369-87. [PMID: 994527 DOI: 10.1016/0022-5193(76)90125-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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30
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Lawley PD, Warren W. Removal of minor methylation products 7-methyladenine and 3-methylguanine from DNA of Escherichia coli treated with dimethyl sulphate. Chem Biol Interact 1976; 12:211-20. [PMID: 764991 DOI: 10.1016/0009-2797(76)90100-9] [Citation(s) in RCA: 71] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Persistence of methylpurines in DNA methylated in vitro and in vivo in Escherichia coli WP2 cells, by dimethyl sulphate (DMS) was studied, with particular reference to the minor products 7-methyladenine and 3-methylguanine, not previously investigated in this respect, but known to be removed from DNA in vitro by spontaneous hydrolysis at neutral pH. The half-life of 7-methyladenine in vivo was relatively short (2.6 +/- 0.2 h) but not significantly shorter than in vitro at pH 7.2, 37 degrees C. The half-life of 3-methylguanine was 3.6 +/- 0.3 h in vivo, markedly shorter than in vitro, where its stability was somewhat greater than that of 7-methylguanine. Enzymatic excision of 3-methylguanine was therefore indicated to occur in E. coli. Previous findings that 7-methylguanine is probably not enzymatically excised from DNA in vivo, whereas 3-methyladenine is rapidly removed, were confirmed, and additional support for the concept of enzymatic removal of 3-methyladenine was obtained by showing extensive inhibition of its removal from cells treated with iodoacetamide prior to methylation. It is suggested that methylations of adenine or guanine in DNA at N-3 constitute blocks to template activity of DNA and stimulate a "repair" response of enzymatic removal of 3-methylpurines. Possible valence bond structures for 3-methylpurine residues in DNA are discussed, leading to the suggestion that ionized forms with positively charged amino groups may be the most effective blocks to template activity.
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Lijinsky W. Interaction with nucleic acids of carcinogenic and mutagenic N-nitroso compounds. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 1976; 17:247-69. [PMID: 778923 DOI: 10.1016/s0079-6603(08)60072-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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32
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Margison GP, Kleihues P. Chemical carcinogenesis in the nervous system. Preferential accumulation of O6-methylguanine in rat brain deoxyribonucleic acid during repetitive administration of N-methyl-N-nitrosourea. Biochem J 1975; 148:521-5. [PMID: 1200992 PMCID: PMC1165571 DOI: 10.1042/bj1480521] [Citation(s) in RCA: 141] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The alkylation of purine bases in DNA of several rat tissues was determined during weekly injections (10 mg/kg) of N-[3H]methyl-N-nitrosourea, a dose schedule known to selectively induce tumours of the nervous system. Each group of animals was killed 1 week after the final injection, and the DNA hydrolysates were analysed by chromatography on Sephadex G-10. After five weekly applications, O6-methylguanine had accumulated in brain DNA to an extent which greatly exceeded that in kidney, spleen and intestine. In the liver, the final O6-methylguanine concentration was less than 1% of that in brain. Between the first and the fifth injection, the O6-methylguanine/7-methylguanine ratio in cerebral DNA increased from 0.28 to 0.68. In addition, 3-methylguanine was found to accumulate in brain DNA whereas in the other organs no significant quantities of this base were detectable. The results are compatible with the hypothesis that O6-alkylation of guanine in DNA plays a major role in the induction of tumours by N-methyl-N-nitrosourea and related carcinogens. The kinetics of the increase of O6-methylguanine in cerebral DNA suggest that there is no major cell fraction in the brain which is capable of excising chemically methylated bases from DNA. This repair deficiency could be a determining factor in the selective induction of nervous-system tumours by N-methyl-N-nitrosourea and other neuro-oncogenic compounds.
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Singer B, Fraenkel-conrat H. Correlation between amino acid exchanges in coat protein of TMV mutants and the nature of the mutagens. Virology 1974; 60:485-90. [PMID: 4367490 DOI: 10.1016/0042-6822(74)90342-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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34
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35
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Nagasawa HT, Shirota FN, Mizuno NS. The mechanism of alkylation of DNA by 5-(3-methyl-1-triazeno)imidazole-4-carboxamide (MIC), a metabolite of DIC (NSC-45388). Non-involvement of diazomethane. Chem Biol Interact 1974; 8:403-13. [PMID: 4858713 DOI: 10.1016/0009-2797(74)90046-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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36
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Lawley PD, Shah SA, Orr DJ. Methylation of nucleic acids by 2,2-dichlorovinyl dimethyl phosphate (dichlorvos, DDVP). Chem Biol Interact 1974; 8:171-82. [PMID: 4595853 DOI: 10.1016/0009-2797(74)90039-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Kramer BS, Fenselau CC, Ludlum DB. Reaction of BCNU (1,3-bis (2-chloroethyl)-1-nitrosourea) with polycytidylic acid. Substitution of the cytosine ring. Biochem Biophys Res Commun 1974; 56:783-8. [PMID: 4826878 DOI: 10.1016/0006-291x(74)90673-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Goth R, Rajewsky MF. Molecular and cellular mechanisms associated with pulse-carcinogenesis in the rat nerbous system by ethyinitrosourea: ethylation of nucleic acids and elimination rates of ethylated bases from the DNA of different tissues. ZEITSCHRIFT FUR KREBSFORSCHUNG UND KLINISCHE ONKOLOGIE. CANCER RESEARCH AND CLINICAL ONCOLOGY 1974; 82:37-64. [PMID: 4280214 DOI: 10.1007/bf00304382] [Citation(s) in RCA: 148] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Kleihues P, Patzschke K, Margison GP, Wegner LA, Mende C. Reaction of methyl methanesulphonate with nucleic acids of fetal and newborn rats in vivo. ZEITSCHRIFT FUR KREBSFORSCHUNG UND KLINISCHE ONKOLOGIE. CANCER RESEARCH AND CLINICAL ONCOLOGY 1974; 81:273-83. [PMID: 4372827 DOI: 10.1007/bf00305030] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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O'Connor PJ, Capps MJ, Craig AW. Comparative studies of the hepatocarcinogen N,N-dimethylnitrosamine in vivo: reaction sites in rat liver DNA and the significance of their relative stabilities. Br J Cancer 1973; 27:153-66. [PMID: 4694387 PMCID: PMC2008841 DOI: 10.1038/bjc.1973.19] [Citation(s) in RCA: 122] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The reaction of the hepatocarcinogen N,N-dimethylnitrosamine has been compared with that of methyl methanesulphonate, a methylating agent which is not a liver carcinogen. Consistent differences have been observed in the reaction of rat liver DNA in vivo with these agents; O(6)-alkylation and the production of unidentified acid-labile products were distinctive features of the reaction with the carcinogenic nitroso compound but were undetectable or in low yield, respectively, after reaction with the alkyl sulphonate. Evidence has been obtained for the excision of these reaction products in animals treated with the hepatocarcinogen and the significance of their relative stabilities is discussed.
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Lawley PD, Shah SA. Reaction of alkylating mutagens and carcinogens with nucleic acids: detection and estimation of a small extent of methylation at O-6 of guanine in DNA by methyl methanesulphonate in vitro. Chem Biol Interact 1972; 5:286-8. [PMID: 4342450 DOI: 10.1016/0009-2797(72)90033-6] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Gerchman LL, Dombrowski J, Ludlum DB. Synthesis and polymerization of O 6 -methylguanosine 5'-diphosphate. BIOCHIMICA ET BIOPHYSICA ACTA 1972; 272:672-5. [PMID: 5050925 DOI: 10.1016/0005-2787(72)90527-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Lawley PD, Shah SA. Methylation of ribonucleic acid by the carcinogens dimethyl sulphate, N-methyl-N-nitrosourea and N-methyl-N'-nitro-N-nitrosoguanidine. Comparisons of chemical analyses at the nucleoside and base levels. Biochem J 1972; 128:117-32. [PMID: 4673570 PMCID: PMC1173576 DOI: 10.1042/bj1280117] [Citation(s) in RCA: 162] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
1. The following methods for hydrolysis of methyl-(14)C-labelled RNA, and for chromatographic isolation and determination of the products, were investigated: enzymic digestion to nucleosides at pH6 or 8; alkaline hydrolysis and conversion into nucleosides; hydrolysis by acid to pyrimidine nucleotides and purine bases, or completely to bases; chromatography on Dowex 50 (NH(4) (+) form) at pH6 or 8.9, or on Dowex 50 (H(+) form), or on Sephadex G-10. 2. The suitability of the various methods for determination of methylation products was assessed. The principal product, 7-methylguanosine, was unstable under the conditions used for determinations of nucleosides. 3- and 7-Methyladenine and 3- and 7-methylguanine are best determined as bases; 1-methyladenine and 3-methylcytosine can be isolated as either nucleosides or bases; O(6)-methylguanine is unstable under the acid hydrolysis conditions used and can be determined as the nucleoside; 3-methyluracil was detected, but may be derived from methylation of the ionized form of uracil. 3. Differences between the patterns of methylation of RNA and homopolyribonucleotides by the N-methyl-N-nitroso compounds and dimethyl sulphate were found: the nitroso compounds were able to methylate O-6 of guanine, were relatively more reactive at N-7 of adenine and probably at N-3 of guanine, but less reactive at N-1 of adenine, N-3 of cytosine and probably at N-3 of uridine. They probably reacted more with the ribose-phosphate chain, but no products from this were identified. 4. The possible influences of these differences on biological action of the methylating agents is discussed. Nitroso compounds may differ principally in their ability to induce miscoding in the Watson-Crick sense by reaction at O-6 of guanine. Both types of agent may induce miscoding to a lesser extent through methylation at N-3 of guanine; both can methylate N atoms, presumably preventing Watson-Crick hydrogen-bonding. N-Methyl-N-nitrosourea can degrade RNA, possibly through phosphotriester formation, but this mechanism is not proven.
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