Nucleic acids reaction with

M. Ya. Feldman, Prog. Nucleic Acid Res. Mol. Biol. 13,1-49 (1973). Nucleic acids, reactions with diethyl pyrocarbonate ... 

Leonov D, Salomon J, Sasson S, Elad D (1973) Ultraviolet- and y-ray-induced reactions of nucleic acid constituents with alcohols. On the selectivity of these reactions for purines. Photochem Photobiol 17 465-468... 

Spectroscopic methods have been complemented by electrochemical methods for investigating the binding strength and specificity of antineo-plasic drugs with DNA at the molecular level, as well as explaining their toxic action. Some tumour cells, but not normal cells, have nucleic acids associated with the cell surface that can suppress many cell immunological reactions. 

The relative rates of reaction of the nucleic acid bases with heavy transition metal ions at neutral pH are in the same order as the relative nucleophilicites of the bases, that is G > A > C > U or T. This order parallels the relative rates of reactions for cA-[(NH3)2Pt(OH2)2] (see Figure 9), while the equilibrium constants for the same reactions are very close in magnitude. In contrast, HsCHgOH, which is more labile to substitution, nndergoes more favorable binding with deprotonation at N-3 of thymine residues in nucleic acids. Thus the relative facilities of individual reactions can lead to differences in initial product formation (kinetic control). Subsequent changes in the metal-nucleic acid complexes can be nnder kinetic or thermodynamic control. 

The pulse radiolysis technique has been used to measure absolute rate constants for reactions of some nucleic acid constituents with Clf radicals (the species produced by reaction of OH radicals with chloride ions in acid aqueous solution). The rate of disappearance of the Cl2 absorption spectrum was measured in the absence and presence of the various solutes. Rate constants for the corresponding OH radical reactions are found to be 20 to 200 times greater than the rate constants for the Clf radical reactions. Steady state radiolysis showed that in some cases the radicals produced by reaction of these compounds with Clf radicals differ in their subsequent reaction from the corresponding OH radical adduct. 

Table I shows rate constants for reaction of some nucleic acid components with Cl2 and with OH radicals. The latter are the data determined by Scholes et al. (5). Also shown are our results from steady state work in which the G-value for base destruction, G (-base), was measured for irradiations carried out in the presence and in the absence of 10 lM sodium chloride at pH 2.7.

Deficiency of either vitamin Bj or folate decreases the synthesis of methionine and SAM, thereby interfering with protein biosynthesis, a number of methylation reactions, and the synthesis of polyamines. In addition, the cell responds to the deficiency by redirecting folate metabolic pathways to supply increasing amounts of methyltetrahydrofolate this tends to preserve essential methylation reactions at the expense of nucleic acid synthesis. With vitamin Bj deficiency, methylenetetrahydro-folate reductase activity increases, directing available intracellular folates into the methyltetrahydrofolate pool (not shown in Figure 53-6). The methyltetrahydrofolate then is trapped by the lack of sufficient vitamin Bj to accept and transfer methyl groups, and subsequent steps in folate metabolism... 

Palecek. E. (1980). Reaction of nucleic acid bases with the mercury electrode determination of purine derivatives at submicromolar concentrations by means of cathodic stripping voltammetry. AwaZ Bzoc/zem 108, 129-138. 

The patterns of autocatalysis with respect to parabolic and exponential reaction courses, which strongly affect the conclusions of Eigen s evolution experiments concerning the decision criteria for mutant selection and coexistence [5 b, 40 h, k], can now be derived from the thermodynamic data of the matrix patterns and their reactivities, and offer quite new views, with autocatalytic cooperation between competitive species [40 k]. Separate from enzyme-catalyzed evolution experiments with RNA and DNA systems, basic questions of prebiotic behavior can for the first time become the subject of detailed experimental research [40 k, 43]. While continuing their studies on more complex autocatalysis patterns, von Kie-drowski et al. diagnosed modulation of molecular recognition as an operational deficit of earlier artificial self-replicational nucleic acid systems with regard to exponential reaction courses, and identified it as an ideal aim for future models [44]. On its way to the nucleoprotein system, evolution must have... 

Dihydropyran derivatives were synthesized as follows 2-(tosyloxymethyl)-3,4-dihydro-2H-pyran was prepared by the reaction of tosyl chloride with 2-(hydroxymethyl)-3,4-dihydro-2H-pyran, which was obtained by reduction of 2-formyl-3,4-dihydro-2H-pyran, Diels-Alder product of acrolein, with the aid of NaBH4. Syntheses of 2-(nucleic acid base methyl)-3,4-dihydro-2H-pyrans were achieved by treatment of sodium salts of the corresponding nucleic acid bases with 2-(tosyloxymethyl)-3,4-dihydro-2H-pyran in dimethylformamide. In order to facilitate its copolymerization with maleic anhydride, the amino group of adenine was blocked by acetyl group. 

This chapter summarizes the results of experimental and theoretical studies on the interactions of nucleic acid bases with minerals, water and sodium cation. The computational study to some extent supported experimentally proposed Wachtershauser s cycle (the production of acetic acid from CO and CH3SH) [9]. It was shown that Fe-Ni-S surface model as catalyst can partially catalyze this reaction through the creation of different coordination complexes [138]. But synthesis of formic acid from CO2 and H2S in the presence of pyrite was shown to be endergonic under modeled conditions. The simulations show that this reaction pathway does not lead to sufficient amount of the product in isolated systems and the cycle can possibly operate at low rates. But to make the final conclusion about the rates, the kinetic study based on reaction rates needs to be performed and inclusion of conditions close to those that occurred on the early Earth, are required to confirm feasibility of studied prebiotic reactions. 

Until recently, it was thought that all enzymes are proteins. But this dogma of biochemistry was recently overthrown by the discovery that some types of RNA can function as biocatalysts. They can cut, splice, and assemble themselves without any outside help from conventional enzymes. This discovery of ribozymes, as they are called, had a major impact on theories of the origin of life. The question was Which came first in the primordial soup from which life began, the proteins or the nucleic acids Proteins could be enzymes and catalyze the reactions needed for life, but they could not store genetic information. The reverse was thought to be true for nucleic acids. But, with the discovery of catalytic activity in certain types of RNA, it now seems almost certain that the earth of 4 billion years ago... 

Fig. 1 Cycloaddition reactions employed in nucleic acid labeling with reporter groups (green star). A Cu -mediated azide-alkyne cycloaddition (CuAAC) of a terminal alkyne with an azide. B Strain-promoted azide-alkyne cycloaddition (SPAAC) of an azide with a cyclooctyne derivative. C Staudinger ligation of an azide with a phosphine derivative (not a cycloaddition reaction, see below). D Norbornene cycloaddition of a nitrile oxide as 1,3-dipole and a norbornene as dipolarophile. E Inverse electron-demand Diels- Alder cycloaddition reaction between a strained double bond (norbornene) and a tetrazine derivative. F Photo-cUck reaction of a push-pull-substituted diaiyltetrazole with an activated double bond (maleimide)...

A very interesting method of polycondensation of active esters containing nucleic acid bases with diamines was described by Hattori and co-workers (87). Di-p-nitrophenyl methylsuccinate with thymine or theophylline was condensed with piperazine. The reaction was carried out in a pyridine/methylene chloride mixture or dimethyl formamide (DMF) in the presence of a copolymer of styrene and styrene derivatives with adenine groups as a template. The strong interaction between the complementary groups (adenine in the template and thymine in the monomer) leads to the template effect. The maximum acceleration effect was observed for copol5uners with adenine content about 54% in the case of polycondensation with piperazine. 

A method combining nucleic acid amplification with high-resolution MS detection relies on very accurate measurement of masses of polymerase chain reaction (PCR) products to infer the base composition (Hofstadler et al. 2005 Ecker et al. 

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