Effects of the ionic environment on modification of yeast tyrosine transfer ribonucleic acid with N-acetoxy-2-acetylaminofluorene

It is generally acknowledged that geometrical and conformational properties of biopolymers have an important effect on their biochemical behaviour. It is less easily recognized that these properties depend also on their macromolecular electronic characteristics.The aim of this review is to demonstrate the significance of such macromolecular electronic effects. Particularly useful for this sake is the recently much developed concept of ‘molecular electrostatic potential’ (MEP) (Scrocco & Tomasi, 1973, 1978) by which is defined the electrostatic (Coulomb) potential created in the neighbouring space by the nuclear charges and the eletronic distribution of a molecule.

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“…(2) carbodiimide (Rhodes, 1975); (3) ./V-acetoxy-2-acetylaminofluorene (Fujimura et al 1972;Pulkrabek et al 1974;Sprinzl et al 1980).…”

Section: (B) Complete Treatment: Potentials and Accessibilities At Rementioning

confidence: 99%

Molecular electrostatic potential of the nucleic acids

Pullman

1981

Quart. Rev. Biophys.

423

269

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“…We have studied four reactions of tRNAPhe: with (i) kethoxal (16)(17) (ii) I2/TlCl.3 (18), (iii.) carbodiimide (19) and (iv) N-acetoxy-2-acetylaminofluorene (20)(21)(22)(23). Each of these reactants interacts with specific sites on specific types of base within tRNAPhe.…”

Section: C) Correlations With Experi_mental_ly Observed Chemical Reacmentioning

confidence: 99%

The electrostatic molecular potential of tRNA^Phe. IV. The potentials and steric accessibilities of sites associated with the bases

Lavery

Pullman

et al. 1980

Nucl Acids Res

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The sites of the 76 nucleic acid bases of tRNAPhe potentially reactive towards electrophiles are studied by calculations on the associated molecular electrostatic potentials and the static steric accessibilities. Each of these sites is treated in its environment within the macromolecule. The influence of various schemes of screening by countercations of the backbone phosphates on the electrostatic potentials is investigated. The possible significance of the potentials and accessibilities in connection with observed chemical reactivities is discussed.

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“…et al, 1970, 1974;Nelson et al, 1971), RNA(Grunberger and Weinstein, 1971;Fujimura et al, 1972;Pulkrabek et al, 1974), and native DNA(Levine et al, 1974;Yamasaki et al, 1977).We proposed a specific three-dimensional conformation at the 3128 BIOCHEMISTRY, VOL.16, NO14, 1977 sites of AAF modification which we named the "base displacement model"(Levine et al, 1974;Weinstein and Grunberger, 1974;Grunberger and Weinstein, 1976). Separate studies of AAF modified DNA(Fuchs and Daune, 1974;Fuchs et al, 1976) have led to a similar model.…”

mentioning

confidence: 99%

Conformation of DNA modified with a dihydrodiol epoxide derivative of benzo[a]pyrene

Pulkrabek¹,

Leffler²,

Weinstein³

et al. 1977

Biochemistry

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The conformation of calf thymus DNA modified by reaction with (+/-)-7beta,8alpha-dihydroxy-9alpha,10alpha-epoxy7,8,9,10-tetrahydrobenzo[a]pyrene, which binds covalently mainly to the 2-amino group of guanosine residues, was studied. With samples in which 1.5 or 2.2% of the bases were modified, there was a slight decrease in Tm during heat denaturation and a slight increase in susceptibility to the single strand specific nuclease S1. In a DNA sample in which 4.5% of the bases were modified, there was an appreciable decrease in Tm and a marked increase in susceptibility to S1 nuclease. The kinetics of the reaction of the modified DNAs with formaldehyde provided evidence for locally destabilized regions ranging from 1 to 7 base plates, depending on the extent of modification. Alkaline and neutral sucrose gradient analyses revealed no evidence for strand breakage in the 1.5 and 2.2% modified samples, although single-strand breaks were found in the 4.5% modified samples. Taken together, these results suggest that DNA molecules containing a covalently bound benzo[a]pyrene derivative have an altered conformation characterized by small localized regions which are destabilized and easily denatured. The conformational changes associated with the covalent binding of the benzo[a]pyrene derivative to native DNA appear to be different from, and less marked, than those associated with the covalent binding of N-2-acetylaminofluorene to native DNA.

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Effects of the ionic environment on modification of yeast tyrosine transfer ribonucleic acid with N-acetoxy-2-acetylaminofluorene

Cited by 10 publications

References 29 publications

Molecular electrostatic potential of the nucleic acids

Molecular electrostatic potential of the nucleic acids

The electrostatic molecular potential of tRNA^Phe. IV. The potentials and steric accessibilities of sites associated with the bases

Conformation of DNA modified with a dihydrodiol epoxide derivative of benzo[a]pyrene

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Effects of the ionic environment on modification of yeast tyrosine transfer ribonucleic acid with N-acetoxy-2-acetylaminofluorene

Cited by 10 publications

References 29 publications

Molecular electrostatic potential of the nucleic acids

Molecular electrostatic potential of the nucleic acids

The electrostatic molecular potential of tRNAPhe. IV. The potentials and steric accessibilities of sites associated with the bases

Conformation of DNA modified with a dihydrodiol epoxide derivative of benzo[a]pyrene

Contact Info

Product

Resources

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The electrostatic molecular potential of tRNA^Phe. IV. The potentials and steric accessibilities of sites associated with the bases