RNA binding small molecules: Studies on t-RNA binding by cytotoxic plant alkaloids berberine, palmatine and the comparison to ethidium
Metadata of CSIR Papers
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| Title |
RNA binding small molecules: Studies on t-RNA binding by cytotoxic plant alkaloids berberine, palmatine and the comparison to ethidium
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| Creator |
Islam, M
Sinha, R Kumar, GS |
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| Subject |
Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical
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| Description |
The interaction of two natural protoberberine plant alkaloids berberine and palmatine with t-RNA(phc) was studied using various biophysical techniques and the data was compared with the binding of the classical DNA intercalator, ethidium. The results of optical thermal melting, differential scanning calorimetry and circular dichroism characterized the native cloverleaf structure of t-RNA under the conditions of the study. The strong binding of the alkaloids and ethidium to t-RNA was revealed from the absorption and fluorescence studies. The salt dependence of the binding constants enabled the dissection of the binding free energy to electrostatic and non-electrostatic contributions. This analysis revealed a surprisingly large favourable component of the non-electrostatic contribution to the binding of these charged alkaloids and ethidium to t-RNA. Isothermal titration calorimetric studies revealed that the binding of both the alkaloids is driven by a moderately favourable enthalpy decrease and a moderately favourable entropy increase while that of ethidium is driven by a large favourable enthalpy decrease. Taken together, the results suggest that the binding of these alkaloid molecules on the t-RNA structure appears to be mostly by partial intercalation while ethidium intercalates to the t-RNA. These results reveal the molecular aspects on the interaction of these alkaloids to t-RNA. (c) 2006 Elsevier B.V All rights reserved.
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| Publisher |
ELSEVIER SCIENCE BVAMSTERDAMPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
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| Date |
2011-09-20T12:12:40Z
2011-09-20T12:12:40Z 2007 |
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| Type |
Article
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| Identifier |
BIOPHYSICAL CHEMISTRY
0301-4622 http://hdl.handle.net/123456789/14370 |
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| Language |
English
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