Journal of Chemical Sciences

, Volume 117, Issue 6, pp 649–655 | Cite as

Mechanism of interaction of vincristine sulphate and rifampicin with bovine serum albumin: A spectroscopic study

  • Bhalchandra P. Kamat
  • Jaldappa Seetharamappa


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.


Vincristine sulphate rifampicin fluorescence quenching mechanism 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Challa V K and Tolosa L M 1993J. Phys. Chem. 97 13914CrossRefGoogle Scholar
  2. 2.
    Aki H and Yamamoto M 1990J. Pharm. Pharmacol. 42 637Google Scholar
  3. 3.
    Aki H and Yamamoto M 1989J. Pharm. Pharmacol. 41 674Google Scholar
  4. 4.
    Miyoshi T, Sukimoto K and Otagiri M 1992J. Pharm. Pharmacol. 44 28Google Scholar
  5. 5.
    Maruyama T, Otagiri M and Takadate A 1990Chem. Pharm. Bull. 38 1688Google Scholar
  6. 6.
    Hamabata A, Chang S and Von-Hippel P H 1973Biochemistry 12 1278CrossRefGoogle Scholar
  7. 7.
    Weber G and Young L B 1964J. Biol. Chem. 239 1415Google Scholar
  8. 8.
    Maruyama T, Otagiri M and Schulman S G 1990Int. J. Pharm. 59 137CrossRefGoogle Scholar
  9. 9.
    Ward L D 1985Methods Enzymol. 117 400CrossRefGoogle Scholar
  10. 10.
    Lakowicz J R 1983 InPrinciples of fluorescence spectroscopy (New York: Plenum) p. 260Google Scholar
  11. 11.
    Eftink M R and Ghiron C A 1981Anal. Biochem. 114 199CrossRefGoogle Scholar
  12. 12.
    Eftink M R and Ghiron C A 1976J. Phys. Chem. 80 486CrossRefGoogle Scholar
  13. 13.
    Willliams E J, Herskovits T T and Laskowski M 1965J. Biol. Chem. 240 3574Google Scholar
  14. 14.
    Yamini H S, Mookandi K and Balachandran U N 1999Biochem. Biophys. Res. Commun. 265 311CrossRefGoogle Scholar

Copyright information

© Indian Academy of Sciences 2005

Authors and Affiliations

  1. 1.Department of ChemistryKarnatak UniversityDharwadIndia

Personalised recommendations