Biochemical Effects of Ethidium Bromide in Micro-organisms

Tomchick, Robert; Mandel, H. George

doi:10.1099/00221287-36-2-225

Cited by 59 publications

(15 citation statements)

References 22 publications

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“…They agree well with those previously obtained by Yielding et al 39 Third, KBpp and TnD were determined from the Scatchard" equation (10) where T 8 D is the ratio of bound dye to total nucleotide concentration, i.e., = 'CD/~CDNA, and FCD is the free dye concentration, Le., FCD = TCD -B C , . According to this treatment, a plot of T8D/FCD vs T 8 D should yield a straight line of gradient K, , with the intercept on the T81, axis equal to TnD.…”

Section: 2mentioning

confidence: 94%

Absorption spectroscopy and dynamic and static light-scattering studies of ethidium bromide binding to calf thymus DNA: implications for outside-binding and intercalation

Nordmeier¹

1992

J. Phys. Chem.

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By combining absorption and light-scattering spectroscopy, including photon correlation and angular distribution of absolute scattered intensity, we have studied the modes of ethidium bromide binding to calf thymus DNA at constant temperature and pH. It is found that the fraction of total bound dye molecules per nucleotide, T8D, is dependent on the counterion concentration, Cs T 8 D decreases slightly as C, is raised. Furthermore, the data indicate two modes of dye binding: intercalation and outside binding. The analysis of the Scatchard plots by Manning's polyelectrolyte theory of site-binding equilibria suggests ( I ) '8D, the fraction of intercalated dye molecules per nucleotide, increases continually with T8D, (2) over the experimental accessible range of T8D, intercalation is the stronger mode of binding, and (3) dye binding appears to be saturated when '8D = T8D. The light-scattering measurements gave useful data for the DNA radius of gyration, ( S ) z , the DNA radius of hydration, Rh, the second virial coefficient, A2, and the DNA translational diffusion coefficient, Dz*o. These data were analyzed in terms of the wormlike chain and the sliding rod model. It is found that each intercalated EBr molecule adds a length of 0.27 nm to the total contour length of CT-DNA. Interestingly, the DNA persistence length of bending, I,, is smaller in the presence than in the absence of EBr. This indicates that dye binding reduces the DNA rigidity due to a neutralization of phosphate groups. Finally, it was shown that the angular dependence of the apparent diffusion coefficient, D (q2), is well simulated by the Rouse-Zimm polymer model comprised of a number of subchains and an apparent subchain d8usion coefficient DPIat that scales as TIT. In particular, it is found that the Rouse-Zimm subchain extension, RZbs, is twice the effective persistence length, which is the weighted sum of the persistence length due to bending, twisting, and contraction/extension. A further result is that the ionic strength dependence of I, can be well described by Manning's theory of territorial counterion binding and that a process such as spontaneous transient opening of DNA base pairs becomes important, if at all, when the ionic strength tends to zero.

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Section: 2mentioning

confidence: 94%

Absorption spectroscopy and dynamic and static light-scattering studies of ethidium bromide binding to calf thymus DNA: implications for outside-binding and intercalation

Nordmeier¹

1992

J. Phys. Chem.

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“…The difference in the relative magnitude of effects in Escherichia coli and Bacillus cereus may be due to a less stringent control of RNA synthesis in B. cereus, since RNA synthesis was also more susceptible to inhibition by a related growth inhibitor, ethidium, in B. cereus than it was in E. coli (Tomchick & Mandel, 1964). In most other biological systems tested quinacrine affects DNA synthesis preferentially.…”

Section: L Seligman a N D H G M A N D E Lmentioning

confidence: 97%

Inhibition of Growth and RNA Biosynthesis of Bacillus cereus by Quinacrine

Seligman

Mandel

1971

Journal of General Microbiology

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SUMMARYThe addition of 0.4 mmquinacrine to exponential cultures of Bacillus cereus led to the complete inhibition of growth, measured turbidimetrically. Certain metal ions such as Ca2+ and Mg2+ were partially effective in preventing growth inhibition, as was the polyamine spermine.Quinacrine inhibited most biosynthetic processes measured to the same extent as the reduction in the rate of growth. Thus the incorporation of amino acids into protein, that of diaminopimelic acid into bacterial wall, the accumulation of Kf and the uptake of nicotinic acid were diminished only in accordance with the decreased rate of turbidimetric increase. DNA biosynthesis was decreased to a lesser extent than was turbidity and continued even after growth had ceased altogether, thus indicating less inhibition of this process than that of protein formation. RNA synthesis, on the other hand, was selectively inhibited in these cells. The depressant effect was most pronounced when ribosomal or rRNA formation was examined. RNA isolated from drug-treated cells still exhibited messenger function. An additional effect of quinacrine on the uptake of certain nucleic acid bases is also postulated. The relative content of ATP in the cells was considerably increased by drug treatment.It appears that quinacrine did not exert its major action on DNA biosynthesis but selectively blocked RNA formation while that of DNA was permitted to continue.

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“…2B). This was somewhat surprising given that EtBr is a known inhibitor of nucleic acid synthesis in vivo [18] and in vitro [19]. EtBr binds more avidly to RNA than DNA [5] and given that egg extracts contain large quantities of RNA, it is possible that RNA sequesters the drug thereby preventing inhibition.…”

Section: Dna Intercalators and Dna Replicationmentioning

confidence: 92%

DNA intercalators differentially affect chromatin structure and DNA replication in Xenopus egg extract

Kumar¹,

Brown²,

Leno³

2004

Anti-Cancer Drugs

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In this paper, we describe a scheme utilizing the Xenopus egg extract system to simultaneously evaluate DNA-interacting drugs as potential anti-cancer agents and gain insights into the mechanisms of drug action. We studied two DNA intercalators, daunomycin (DM), a cancer chemotherapeutic, and ethidium bromide (EtBr), a compound with no reported therapeutic value. Consistent with our earlier report, we find that DM inhibits DNA replication in a concentration-dependent manner. In contrast, EtBr does not inhibit replication over the same concentration range. The environment in which drug-DNA interactions take place is an important determinant of the effect of the drug on DNA replication. While neither intercalator inhibits nuclear membrane assembly nor nuclear protein import, DM does disrupt chromatin structure at very low concentrations, whereas EtBr does not. This system may prove useful for large scale screening of DNA-interacting chemotherapeutic compounds in a cellular milieu.

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Biochemical Effects of Ethidium Bromide in Micro-organisms

Cited by 59 publications

References 22 publications

Absorption spectroscopy and dynamic and static light-scattering studies of ethidium bromide binding to calf thymus DNA: implications for outside-binding and intercalation

Absorption spectroscopy and dynamic and static light-scattering studies of ethidium bromide binding to calf thymus DNA: implications for outside-binding and intercalation

Inhibition of Growth and RNA Biosynthesis of Bacillus cereus by Quinacrine

DNA intercalators differentially affect chromatin structure and DNA replication in Xenopus egg extract

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