Molecular recognition of two bioactive coumarin derivatives 7-hydroxycoumarin and 4-methyl-7-hydroxycoumarin by hen egg white lysozyme : Exploring the binding mechanism, thermodynamic parameters and structural changes using multispectroscopic and computational approaches

Multispectroscopic and computational methods of exploring the interaction between a carrier protein and therapeutic compounds provide a preliminary investigation into establishing the efficacy of such compounds. Here, two coumarin derivatives, 7-hydroxycoumarin (7-HC) and 4-methyl-7-hydroxycoumarin (4-Me-7-HC), were selected to carry out numerous biophysical interaction studies with a model carrier protein, hen egg white lysozyme (HEWL). Fluorescence spectroscopy studies conducted between HEWL and 7-HC/4-Me-7-HC revealed the binding constants (Kb) were in the range of 104 M-1, indicating a moderate nature of binding. The quenching mechanism observed during complexation process was an unusual static quenching due to the effect of temperature on the rate constant. Thermodynamic parameters revealed a positive ΔH and ΔS for HEWL-7-HC/4-Me-7-HC, indicating hydrophobic forces played a dominant role in the interaction process. FRET studies suggested a possible non-radiative energy transfer from the donor (HEWL) to the acceptor (coumarins). Molecular docking studies revealed the interaction of 7-HC/4-Me-7-HC with intrinsic fluorophores, Trp63 and Trp108, Trp108 being an essential residue for binding as proven by molecular dynamic (MD) simulation. MD simulation studies also indicated conformational stability gained by HEWL upon interaction with 7-HC and 4-Me-7-HC. The microenvironment surrounding the Trp residues showed a significant Stoke's shift on carrying out 3-D fluorescence. CD studies revealed a decrease in the alpha helical content of HEWL upon interacting with the ligands. Enzymatic assay conducted for HEWL in the presence of 7-HC/4-Me-7-HC saw an increase in the activity of HEWL, suggesting a change in structural conformation and stability of the protein, altering its activity.Communicated by Ramaswamy H. Sarma.

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:40

Enthalten in:

Journal of biomolecular structure & dynamics - 40(2022), 24 vom: 01., Seite 13872-13888

Sprache:

Englisch

Beteiligte Personen:

Lyndem, Sona [VerfasserIn]
Gazi, Rabiul [VerfasserIn]
Jana, Madhurima [VerfasserIn]
Belwal, Vinay Kumar [VerfasserIn]
Singha Roy, Atanu [VerfasserIn]

Links:

Volltext

Themen:

4-methyl-7-hydroxycoumarin
7-hydroxycoumarin
Carrier Proteins
Coumarins
Docking
EC 3.2.1.17
Fluorescence
Hen egg white lysozyme
Journal Article
Muramidase
Quenching
Research Support, Non-U.S. Gov't
Umbelliferones

Anmerkungen:

Date Completed 28.12.2022

Date Revised 28.02.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1080/07391102.2021.1995499

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM332891089