Conformational aspects of poly(dI-dC).poly(dI-dC) and poly(dG-dC).poly(dG-dC) on binding of the alkaloid, berberine chloride.
Interaction of berberine chloride with poly(dI-dC).poly(dI-dC) and poly(dG-dC).poly(dG-dC) has been studied by various spectroscopic methods. Comparative data on binding parameters, fluorescence enhancement and Tm measurements indicate a stronger binding of berberine to the IC polymer than to the GC one. Conformational changes as monitored by circular dichroic spectra indicate change of the unusual circular dichroism of poly(IC) to a conformation similar to A-conformation, while in poly(GC) only a B-conformational change is observed. Extrinsic CD bands developed in the visible absorption region of berberine on interaction with poly(IC) are of much higher intensity compared to poly(GC). It is concluded that berberine induces a conformational change similar to the A-conformation on binding to poly(IC).
Kumar
G S
GS
Biophysical Chemistry Laboratory, Indian Institute of Chemical Biology, Calcutta.
Debnath
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Maiti
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D001599:Berberine / Q000737:chemistry / Q000378:metabolism*; D002021:Buffers; D002942:Circular Dichroism; D007700:Kinetics; D009690:Nucleic Acid Conformation; D011089:Polydeoxyribonucleotides / Q000737:chemistry* / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry / Q000379:methods
D002021:Buffers; D011089:Polydeoxyribonucleotides; D001599:Berberine; C031156:poly d(I-C); C019530:poly(dC-dG)