Abstract
The mechanism of interaction of vincristine sulphate (VS) and rifampicin (RF) with bovine serum albumin (BSA) has been studied by quenching of BSA fluorescence by RF/VS. The Stern-Volmer plot indicates the presence of a static component in the quenching mechanism. Results also show that both the tryptophan residues of BSA are accessible to VS and RF. The high magnitude of rate constant of quenching indicates that the process of energy transfer occurs by intermolecular interaction and VS/RF-binding site is in close proximity to the tryptophan residues of BSA. Binding studies in the presence of a hydrophobic probe, 8-anilino-1-naphthalene-sulphonic acid sodium salt (ANS) indicate that the VS and RF compete with ANS for hydrophobic sites on the surface of BSA. Small decreases in critical micellar concentrations (CMC) of anionic surfactants in presence of VS/ RF show that the ionic character of VS/RF also contributes to binding. The temperature dependence of the association constant is used to estimate the values of the thermodynamic parameters involved in the interaction of VS/RF with BSA and the results indicate that hydrophobic forces play a significant role in the binding. Circular dichroism studies reveal that the change in helicity of BSA are due to binding of VS/RF to BSA.
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References
Challa V K and Tolosa L M 1993J. Phys. Chem. 97 13914
Aki H and Yamamoto M 1990J. Pharm. Pharmacol. 42 637
Aki H and Yamamoto M 1989J. Pharm. Pharmacol. 41 674
Miyoshi T, Sukimoto K and Otagiri M 1992J. Pharm. Pharmacol. 44 28
Maruyama T, Otagiri M and Takadate A 1990Chem. Pharm. Bull. 38 1688
Hamabata A, Chang S and Von-Hippel P H 1973Biochemistry 12 1278
Weber G and Young L B 1964J. Biol. Chem. 239 1415
Maruyama T, Otagiri M and Schulman S G 1990Int. J. Pharm. 59 137
Ward L D 1985Methods Enzymol. 117 400
Lakowicz J R 1983 InPrinciples of fluorescence spectroscopy (New York: Plenum) p. 260
Eftink M R and Ghiron C A 1981Anal. Biochem. 114 199
Eftink M R and Ghiron C A 1976J. Phys. Chem. 80 486
Willliams E J, Herskovits T T and Laskowski M 1965J. Biol. Chem. 240 3574
Yamini H S, Mookandi K and Balachandran U N 1999Biochem. Biophys. Res. Commun. 265 311
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Kamat, B.P., Seetharamappa, J. Mechanism of interaction of vincristine sulphate and rifampicin with bovine serum albumin: A spectroscopic study. J Chem Sci 117, 649–655 (2005). https://doi.org/10.1007/BF02708294
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DOI: https://doi.org/10.1007/BF02708294