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Comprehensive Study of the Interaction Between a Potential Antiprion Cationic Porphyrin and Human Prion Protein at Different pH by Using Multiple Spectroscopic Methods
- Source :
- Journal of Pharmaceutical Sciences. 102:1076-1085
- Publication Year :
- 2013
- Publisher :
- Elsevier BV, 2013.
-
Abstract
- Cationic porphyrins are potential antiprion drugs; however, the action mechanisms remain poorly understood. Herein, the interaction between a cationic porphyrin and recombinant human prion protein (rPrP C ) was comprehensively studied by using surface plasmon resonance (SPR), fluorescence, resonance light scattering (RLS), and circular dichroism (CD) spectroscopy. The experimental results showed that the interaction between the cationic porphyrin and rPrP C was pH dependent. The equilibrium association constants obtained from SPR spectroscopy were 4.12 × 10 3 M − 1 at pH 4.0, 1.74 × 10 5 M − 1 at pH 6.0, and 5.98 × 10 5 M − 1 at pH 7.0. The binding constants at 298 K obtained from the fluorescence quenching method were 7.286 × 10 4 M − 1 at pH 4.0 and 1.45 7 × 10 5 M − 1 at pH 6.0. The thermodynamic parameters such as enthalpy change, entropy change, and free energy change were calculated, and the results indicated hydrogen bonds and van der Waals interactions played a major role in the binding reaction. The RLS experiment was performed to study the influence of porphyrin on the rPrP C aggregation at different pH values. The CD experiments were conducted to investigate the effects of porphyrin on the secondary structure and thermal stability of rPrP C . Finally, the comparison of SPR measurement and fluorescence quenching measurement was discussed.
- Subjects :
- Circular dichroism
Porphyrins
Light
Analytical chemistry
Pharmaceutical Science
Protein Structure, Secondary
Fluorescence spectroscopy
chemistry.chemical_compound
Cations
Humans
Scattering, Radiation
PrPC Proteins
Surface plasmon resonance
Protein secondary structure
Binding Sites
Protein Stability
Chemistry
Hydrogen bond
Circular Dichroism
Cationic polymerization
Hydrogen Bonding
Hydrogen-Ion Concentration
Surface Plasmon Resonance
Porphyrin
Fluorescence
Recombinant Proteins
Spectrometry, Fluorescence
Thermodynamics
Physical chemistry
Protein Binding
Subjects
Details
- ISSN :
- 00223549
- Volume :
- 102
- Database :
- OpenAIRE
- Journal :
- Journal of Pharmaceutical Sciences
- Accession number :
- edsair.doi.dedup.....7fb5b27c9c624baedfb9af264bb58623