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      Permanent link:
      https://www.ias.ac.in/article/fulltext/jcsc/119/02/0077-0082

    • Keywords

       

      Fluorescence resonance energy transfer; photosensitisation; human serum albumin; fluorescence quenching; overlap integral; Stern-Volmer constant.

    • Abstract

       

      The interaction between a bioactive molecule, 3-acetyl-4-oxo-6,7-dihydro-12H indolo-[2,3-a] quinolizine (AODIQ), with human serum albumin (HSA) has been studied using steady-state absorption and fluorescence techniques. A 1 : 1 complex formation has been established and the binding constant (𝐾) and free energy change for the process have been reported. The AODIQ-HSA complex results in fluorescence resonance energy transfer (FRET) from the tryptophan moiety of HSA to the probe. The critical energy-transfer distance ($R_0$) for FRET and the Stern-Volmer constant ($K_{sv}$) for the fluorescence quenching of the donor in the presence of the acceptor have been determined. Importantly, $K_{SV}$ has been shown to be equal to the binding constant itself, implying that the fluorescence quenching arises only from the FRET process. The study suggests that the donor and the acceptor are bound to the same protein at different locations but within the quenching distance.

    • Author Affiliations

       

      Paramita Das1 Arabinda Mallick1 Basudeb Haldar1 Alok Chakrabarty1 Nitin Chattopadhyay1

      1. Department of Chemistry, Jadavpur University, Kolkata 700 032
    • Dates

       
  • Journal of Chemical Sciences | News

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