Mechanism of the isotopic exchange of the C-8 hydrogen of purines in nucleosides and in deoxyribonucleic acid

Tomasz, Maria; Olson, Janet E.; Mercado, Carmen M.

doi:10.1021/bi00757a019

Cited by 77 publications

(58 citation statements)

References 36 publications

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“…This conformation dependence is similar to that reported previously for bisulfite-catalyzed tritium labeling of cytosine residues in DNA [7]. The tritium incorporation into purine bases was obviously due to the well-known exchange at position 8 (see [21] and references cited therein). It should be noted that there is no significant difference in the incorporation into purines between native and denatured DNA.…”

Section: Conformation Dependence Of the Labeling Of Cytosine Residuessupporting

confidence: 88%

Conformation of Escherichia coli Glutamic Acid tRNA II as Studied by Hydrogen‐Tritium Exchange Catalyzed by Cysteine Methyl Ester

Wataya¹,

Lida

Kudo

et al. 1976

European Journal of Biochemistry

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'Incubation of CMP in ,H,O with 0.5 M cysteine methyl ester at p2H 5 and 37 "C for 24 h resulted in 43% exchange of 5-H to 5-2H. No deamination of the cytosine nucleus was noted during this treatment. Native and denatured DNA samples from calf thymus were treated in 3H,0 with cysteine methyl ester at pH 5 and 37 "C for 24 h and incorporation of tritium into each DNA base was determined by enzymic digestion of the treated DNA.The order of the specific radioactivity found was cytosine $ guanine > adenine >> thymine for denatured DNA and guanine > adenine z cytosine > thymine for native DNA. The ratio of radioactivity for denatured/native was 11.6 for cytosine, 1.5 for guanine, 1.8 for adenine and 1.1 for thymine. Hence the incorporation in cytosine under the reaction conditions is preferential for single-stranded, nonhelical regions of DNA.Eschrrichia coli glutamic acid tRNA I1 was treated in 3H20 with 1.24 M cysteine methyl ester at pH 5 and 37 "C. The 24-h-treated tRNA was digested with ribonuclease TI and the fragments were fractionated. Each fragment was then digested with ribonuclease T, into mononucleotides and the radioactivity distribution among the bases was determined. The average radioactivity found for each of the bases of the four major nucleotides was cytosine $ guanine z adenine > uracil.The radioactivity in cytosine varied greatly among the RNase TI fragments, the ratio of the highest to the lowest radioactivity being 18.7. The corresponding value for guanine was 11.1, for adenine 4.73 and for uracil 3.64. Based on the data obtained, it was deduced that in this tRNA the anticodon loop, the dihydrouridine loop and the extra loop were 'exposed' under the conditions employed for the labeling. The 5'-terminal cytosine of the anticodon loop was in a 'non-exposed' state, a situation similar to that previously reported for E. coli tyrosine tRNA [Cashmore, A.

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Section: Conformation Dependence Of the Labeling Of Cytosine Residuessupporting

confidence: 88%

Conformation of Escherichia coli Glutamic Acid tRNA II as Studied by Hydrogen‐Tritium Exchange Catalyzed by Cysteine Methyl Ester

Wataya¹,

Lida

Kudo

et al. 1976

European Journal of Biochemistry

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“…Over the time period (ϳ1000 h) of this NMR study conducted at 30°C, signals entailing all H8 and H2 protons were qualitatively observed to decrease due to exchange with solvent deuterium (56). The exchange rate of guanosine H8 was dependent on the sequence, where that of the 5Ј-terminal residue (G11) was relatively fast (half-life of ϳ500 h compared to Ն1000 h for others).…”

Section: H-13 C Correlation Spectra and 13 C Resonance Assignmentsmentioning

confidence: 83%

DNA Duplex Dynamics: NMR Relaxation Studies of a Decamer with Uniformly13C-Labeled Purine Nucleotides

Kojima

Ono

Kainosho

et al. 1998

Journal of Magnetic Resonance

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“…1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 multiple-labeled isotopologues from simple isotope-labeled synthones such as cyanide, bromoacetate, ammonia and/or nitrite that are all commercially available at moderate costs. [23][24][25][26][27][28][29][30][31][32][33][34] Hence, numerous isotopologues of 6 and of riboflavin carrying single or multiple labels in the heterocyclic part of the respective chromophores can now be prepared as desired for specific spectroscopic problems (cf . Tables 1 and 2 …”

Section: Resultsmentioning

confidence: 99%

Preparation of Flavocoenzyme Isotopologues by Biotransformation of Purines

et al. 2015

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Isotope-labeled flavins are crucial reporters for many biophysical studies of flavoproteins. A purine-deficient Escherichia coli strain engineered for expression of the ribAGH genes of Bacillus subtilis converts isotope-labeled purine supplements into the riboflavin precursor, 6,7-dimethyl-8-ribityllumazine, with yields up to 40%. The fermentation products can subsequently be converted into isotope-labeled riboflavin and the cognate flavocoenzymes, FMN and FAD, by in vitro biotransformation with better than 90% yield. Using this approach, more than 100 single or multiple (13)C-, (15)N-, (17)O-, and (18)O-labeled isotopologues of these cofactors and ligands become easily accessible, enabling advanced ligand-based spectroscopy of flavoproteins and lumazine receptor proteins at unprecedented resolution.

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Mechanism of the isotopic exchange of the C-8 hydrogen of purines in nucleosides and in deoxyribonucleic acid

Cited by 77 publications

References 36 publications

Conformation of Escherichia coli Glutamic Acid tRNA II as Studied by Hydrogen‐Tritium Exchange Catalyzed by Cysteine Methyl Ester

Conformation of Escherichia coli Glutamic Acid tRNA II as Studied by Hydrogen‐Tritium Exchange Catalyzed by Cysteine Methyl Ester

DNA Duplex Dynamics: NMR Relaxation Studies of a Decamer with Uniformly13C-Labeled Purine Nucleotides

Preparation of Flavocoenzyme Isotopologues by Biotransformation of Purines

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