Abstract
Piperlongumine (PPL) is an alkaloid extracted from several pepper species that exhibits anti-inflammatory and anti-carcinogenic properties. Nevertheless, the molecular mode of action of PPL that confers such powerful pharmacological properties remains unknown. From this perspective, spectroscopic methods aided by computational modeling were employed to characterize the interaction between PPL and nucleotide-binding domain of heat shock protein 70 (NBD/HSP70), which is involved in the pathogenesis of several diseases. Steady-state fluorescence spectroscopy along with time-resolved fluorescence revealed the complex formation based on a static quenching mechanism. Van’t Hoff analyses showed that the binding of PPL toward NBD is driven by equivalent contributions of entropic and enthalpic factors. Furthermore, IDF and Scatchard methods applied to fluorescence intensities determined two cooperative binding sites with Kb of (6.3 ± 0.2) × 104 M−1. Circular dichroism determined the thermal stability of the NBD domain and showed that PPL caused minor changes in the protein secondary structure. Computational simulations elucidated the microenvironment of these interactions, showing that the binding sites are composed mainly of polar amino acids and the predominant interaction of PPL with NBD is Van der Waals in nature.
Original language | English |
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Article number | 1298 |
Journal | Pharmaceuticals (Basel, Switzerland) |
Volume | 14 |
Issue number | 12 |
DOIs | |
Publication status | Published - 13 Dec 2021 |
Bibliographical note
Funding Information:The authors A.P.R.P. and G.Z. were recipients of scholarships from Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior?(CAPES), Brazil-Finance Code 001, and Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq), Brazil?(Grant 141953/2017-9), respectively. The author M.L.C. acknowledges the financial support from Funda??o de Amparo ? Pesquisa do Estado de S?o Paulo-FAPESP (Grant 2017/08834-9), Brazil.
Keywords
- heat shock protein
- HSP70
- nucleotide-binding domain
- piperlongumine
- fluorescence spectroscopy
- circular dichroism
- molecular docking
- molecular dynamics
- molecular mechanics
- Poisson–Boltzmann surface area
ASJC Scopus subject areas
- Molecular Medicine
- Pharmaceutical Science
- Drug Discovery