Biophysical insights into the interaction of hen egg white lysozyme with therapeutic dye clofazimine: modulation of activity and SDS induced aggregation of model protein

Abstract

The present study details the binding process of clofazimine to hen egg white lysozyme (HEWL) using spectroscopy, dynamic light scattering, transmission electron microscopy (TEM), and molecular docking techniques. Clofazimine binds to the protein with binding constant (K) in the order of 1.57 × 10 at 298 K. Binding process is spontaneous and exothermic. Molecular docking results suggested the involvement of hydrogen bonding and hydrophobic interactions in the binding process. Bacterial cell lytic activity in the presence of clofazimine increased to more than 40% of the value obtained with HEWL only. Interaction of the drug with HEWL induced ordered secondary structure in the protein and molecular compaction. Clofazimine also effectively inhibited the sodium dodecyl sulfate (SDS) induced amyloid formation in HEWL and caused disaggregation of preformed fibrils, reinforcing the notion that there is involvement of hydrophobic interactions and hydrogen bonding in the binding process of clofazimine with HEWL and clofazimine destabilizes the mature fibrils. Further, TEM images confirmed that fibrillar species were absent in the samples where amyloid induction was performed in the presence of clofazimine. As clofazimine is a drug less explored for the inhibition of fibril formation of the proteins, this study reports the inhibition of SDS-induced amyloid formation of HEWL by clofazimine, which will help in the development of clofazimine-related molecules for the treatment of amyloidosis.

Biophysical Insight into the Interaction of Human Lysozyme with Anticancer Drug Anastrozole: A Multitechnique Approach

“…2 μ M HL was incubated with various molar concentrations of anastrozole at 298 K for two hours and then 10 μ L from each of these solutions was added to 2990 μ L of suspension of 0.3 mg/ml M. lysodeikticus in a quartz cuvette placed in the cuvette holder maintained at 298 K in the cuvette holder of Cary 60 double-beam UV–Vis spectrophotometer (Agilent Technologies). Decrement in absorbance values at 450 nm with time was monitored and used for the activity calculations [ 5 ]. Data obtained with the HL alone were assumed to be 100% and data obtained in the presence of anastrozole were organized with respect to the value obtained with HL alone that is considered as a reference.…”

“…HL is found in secretions such as saliva and tears. It is a model protein [5,6]. Ever since its discovery, lysozyme represented a prototype molecule for understanding the complexity of the protein structure and function [7].…”

Polyols (Glycerol and Ethylene glycol) mediated amorphous aggregate inhibition and secondary structure restoration of metalloproteinase-conalbumin (ovotransferrin)

“…In such trend, that dual function has been displayed by quercetin for the conformation conservation of insulin, which inhibits the fibril formation and also shows disorganizing ability by amyloid fibril (ordered structure) conversion into amorphous aggregates (unordered structure) [25]. In this series, clofazimine inhibits as well as destabilize the fibrils of hen egg white lysozyme [26]. Moreover, Aspartate-␤-semi aldehyde dehydrogenase forms aggregates, via soluble to insoluble polymerization as function of concentration and time.…”

Effect of pH on Diclofenac–Lysozyme Interaction: Structural and Functional Aspect

“…Small ligands are known to intermingle with these molecules readily ( Ajmal et al, 2017a ; Zhang et al, 2020 ). Recently, such studies are hot spots of multidisciplinary research ( Ajmal et al, 2017b ; Zhang et al, 2020 ). Proteins are versatile molecules and perform many different functions in the human body.…”

“…Numerous studies exist implicating the role of DCF in cardiac, renal, and gastrointestinal complications ( Gökçimen et al, 2000 ; Weir, 2002 ; Lewis et al, 2002 ; Baigent et al, 2013 ; Lundgren et al, 2017 ). Lysozyme is a small globular protein used as a model molecule to study the effect of external agents on its stability and functions ( Ajmal et al, 2017b ; Leone et al, 2019 ). Ever since its discovery, lysozyme has represented a prototype molecule for understanding the complexity of its structure and function ( Saadati-Eskandari et al, 2019 ).…”