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EFFECTS OF IONIC STRENGTH and pH ON THE BINDING OF SANGUINARINE TO DEOXYRIBONUCLEIC ACID
Author(s) -
Nandi R.,
Chaudhuri K.,
Maiti M.
Publication year - 1985
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1985.tb01600.x
Subject(s) - sanguinarine , ionic strength , ethidium bromide , chemistry , ionic bonding , intercalation (chemistry) , dna , titration , fluorescence , absorption (acoustics) , salt (chemistry) , binding constant , inorganic chemistry , ion , nuclear chemistry , binding site , alkaloid , stereochemistry , biochemistry , organic chemistry , aqueous solution , physics , quantum mechanics , acoustics
— The interaction of sanguinarine with DN A has been studied in buffers of various ionic strengths and pH values where the physicochemical properties of DNA remain unchanged. Spectrophotometric analysis using absorption and fluorescence techniques indicates that the complex formed between sanguinarine and DNA is a function of ionic strength and pH. Increasing the salt concentration minimizes the importance of intercalator charge and extrapolation to 1 M [Na+] salt reveals the intercalative abilities, as reflected in binding constants, to be of the same order of magnitude as that of ethidium bromide. The fluorescence of sanguinarine bound to DNA is quenched and can be decreased by [Na +], [Mg 2 +] and [Ca 2 +] ions. The influence of pH on the fluorescence spectrum of sanguinarine with increasing concentration of DNA was studied. It is concluded that the binding of sanguinarine to DNA contains a large favourable non‐electrostatic interaction and the alkaloid binds more DNA in buffer of low ionic‐strength and acidic pH.