Spectroscopic and Calorimetric Studies on the Binding of Alkaloids Berberine, Palmatine and Coralyne to Double Stranded RNA Polynucleotides
IR@IICB: CSIR-Indian Institute of Chemical Biology, Kolkata
View Archive Info| Field | Value | |
| Title |
Spectroscopic and Calorimetric Studies on the Binding of Alkaloids Berberine, Palmatine
and Coralyne to Double Stranded RNA Polynucleotides
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| Creator |
Islam, Md. Maidul
Roy Chowdhury, Sebanti Kumar, G Suresh |
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| Subject |
Chemistry
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| Description |
The interaction of two natural protoberberine plant alkaloids berberine and palmatine and a synthetic derivative
coralyne to three double stranded ribonucleic acids, poly(A). poly(U), poly(I).poly(C) and poly(C).poly(G)
was studied using various biophysical techniques. Absorbance and fluorescence studies showed that the alkaloids
bound cooperatively to these RNAs with the binding affinities of the order 104 M-1. Circular dichroic results
suggested that the conformation of poly(A). poly(U) was perturbed by all the three alkaloids, that of
poly(I).poly(C) by coralyne only and that of poly(C).poly(G) by none. Fluorescence quenching studies gave
evidence for partial intercalation of berberine and palmatine and complete intercalation of coralyne to these
RNA duplexes. Isothermal titration calorimetric studies revealed that the binding was characterized by negative
enthalpy and positive entropy changes and the affinity constants derived were in agreement with the overall
binding affinity from spectral data. The binding of all the three alkaloids considerably stabilized the melting
of poly(A). poly(U) and poly(I).poly(C) and the binding data evaluated from the melting data were in agreement
with that obtained from other techniques. The overall binding affinity of the alkaloids to these double stranded
RNAs varied in the order, berberine ) palmatine < coralyne. The temperature dependence of the enthalpy
changes afforded large negative values of heat capacity changes for the binding of palmatine and coralyne to
poly(A).poly(U) and of coralyne to poly(I).poly(C), suggesting substantial hydrophobic contribution in the
binding process. Further, enthalpy-entropy compensation was also seen in almost all the systems that showed
binding. These results further advance our understanding on the binding of small molecules that are specific
binders to double stranded RNA sequences.
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| Publisher |
American Chemical Society
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| Date |
2009
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://www.eprints.iicb.res.in/221/1/JOURNAL_OF_PHYSICAL_CHEMISTRY_B%2C113(4)%2C_1210%2D1224%2C_2009[116].pdf
Islam, Md. Maidul and Roy Chowdhury, Sebanti and Kumar, G Suresh (2009) Spectroscopic and Calorimetric Studies on the Binding of Alkaloids Berberine, Palmatine and Coralyne to Double Stranded RNA Polynucleotides. The Journal of Physical Chemistry B, 113 (4). pp. 1210-1224. |
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| Relation |
http://dx.doi.org/10.1021/jp806597w CCC: $40.75
http://www.eprints.iicb.res.in/221/ |
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