Interactions of Aristololactam ‚-D-Glucoside with Right-Handed and Left-Handed Forms of Synthetic Deoxyribonucleic Acid: Spectroscopic and Thermodynamic Study
IR@IICB: CSIR-Indian Institute of Chemical Biology, Kolkata
View Archive Info| Field | Value | |
| Title |
Interactions of Aristololactam ‚-D-Glucoside with Right-Handed and Left-Handed Forms of Synthetic Deoxyribonucleic Acid: Spectroscopic and Thermodynamic
Study
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| Creator |
Ray, A
Maiti, M |
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| Subject |
Chemistry
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| Description |
The interaction of aristololactam ‚-D-glucoside (ADG) with different polymorphic structures
of poly(dG-me5dC)‚poly(dG-me5dC), poly(dG-dC)‚poly(dG-dC), and poly(dI-dC)‚poly(dI-dC) has been
studied by spectrophotometric, spectrofluorimetric, circular dichroism, UV melting profiles, and
thermodynamic analysis. The binding of ADG to B-form duplexes is characterized by the typical
bathochromic and hypochromic effects in the absorption spectrum, quenching of steady-state fluorescence
intensity, a decrease in fluorescence quantum yield of ADG, an increase in fluorescence polarization
anisotropy, an increase of thermal transition temperature, and perturbation in circular dichroic spectrum.
Scatchard analysis indicates that ADG binds to the right-handed form of each polymer in a noncooperative
manner. Comparative binding parameters determined from absorbance titration by Scatchard analysis,
employing the excluded site model, indicate a stronger binding of ADG to the B-form of poly(dG-me5-
dC)‚poly(dG-me5dC) than to the B-form of poly(dG-dC)‚poly(dG-dC) or poly(dI-dC)‚poly(dI-dC).
Thermodynamic parameters (¢G°, ¢H°, and ¢S°) obtained by van’t Hoff analysis of the data show that
the process of binding to all B-form duplexes is exothermic and enthalpy driven as characterized by a
favorable negative enthalpy change (¢H°). The binding is opposed by a negative entropy change (¢S°)
contribution. Conformational changes indicate that the alkaloid converts the left-handed form of poly-
(dG-dC)‚poly(dG-dC), and its methylated analogue and high salt form of poly(dI-dC)‚poly(dI-dC) to a
bound right-handed form, while it inhibits both the rate and extent of the B to Z transition. These studies
reveal that ADG binds strongly to B-form polymers while it does not bind to polymers of Z-form.
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| Date |
1996
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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/702/1/BIOCHEMISTRY%2C_35(_23)%2C_7394%2D7402_[35].pdf
Ray, A and Maiti, M (1996) Interactions of Aristololactam ‚-D-Glucoside with Right-Handed and Left-Handed Forms of Synthetic Deoxyribonucleic Acid: Spectroscopic and Thermodynamic Study. Biochemistry, 35 (23). pp. 7394-7402. |
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| Relation |
http://dx.doi.org/10.1021/bi9515329
http://www.eprints.iicb.res.in/702/ |
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