A biophysical study on the mechanism of interactions of DOX or PTX with α-lactalbumin as a delivery carrier

Sci Rep. 2018 Nov 26;8(1):17345. doi: 10.1038/s41598-018-35559-1.

Abstract

Doxorubicin and paclitaxel, two hydrophobic chemotherapeutic agents, are used in cancer therapies. Presence of hydrophobic patches and a flexible fold could probably make α-Lactalbumin a suitable carrier for hydrophobic drugs. In the present study, a variety of thermodynamic, spectroscopic, computational, and cellular techniques were applied to assess α-lactalbumin potential as a carrier for doxorubicin and paclitaxel. According to isothermal titration calorimetry data, the interaction between α-lactalbumin and doxorubicin or paclitaxel is spontaneous and the K (M-1) value for the interaction of α-lactalbumin and paclitaxel is higher than that for doxorubicin. Differential scanning calorimetry and anisotropy results indicated formation of α-lactalbumin complexes with doxorubicin or paclitaxel. Furthermore, molecular docking and dynamic studies revealed that TRPs are not involved in α-Lac's interaction with Doxorubicin while TRP 60 interacts with paclitaxel. Based on Pace analysis to determine protein thermal stability, doxorubicin and paclitaxel induced higher and lower thermal stability in α-lactalbumin, respectively. Besides, fluorescence lifetime measurements reflected that the interaction between α-lactalbumin with doxorubicin or paclitaxel was of static nature. Therefore, the authors hypothesized that α-lactalbumin could serve as a carrier for doxorubicin and paclitaxel by reducing cytotoxicity and apoptosis which was demonstrated during our in vitro cell studies.

MeSH terms

  • Calorimetry / methods
  • Calorimetry, Differential Scanning
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Circular Dichroism
  • Doxorubicin / chemistry*
  • Doxorubicin / pharmacokinetics
  • Drug Carriers / adverse effects
  • Drug Carriers / chemistry*
  • Drug Carriers / pharmacokinetics
  • Drug Delivery Systems / methods
  • Drug Liberation
  • Fluorescence Polarization
  • Humans
  • Hydrogen Bonding
  • Lactalbumin / administration & dosage
  • Lactalbumin / chemistry*
  • Lactalbumin / metabolism
  • Molecular Docking Simulation
  • Paclitaxel / chemistry*
  • Paclitaxel / pharmacokinetics
  • Protein Stability
  • Thermodynamics

Substances

  • Drug Carriers
  • Doxorubicin
  • Lactalbumin
  • Paclitaxel