Interaction of caffeine and sulfadiazine with lysozyme adsorbed at colloidal metal nanoparticle interface: influence on drug transport ability and antibacterial activity

Abstract

The modulated bioactivity of proteins immobilized on nanoparticle (NP) interfaces is of tremendous interest toward designing better therapeutic and diagnostic tools. In this work, binding behavior and the antibacterial activity of free lysozyme (LYS) as well as its non-covalent assembly with silver (Ag) and gold (Au) colloidal NPs were compared in presence of two model drugs, viz. sulfadiazine (SDZ) and caffeine (CAF). Intrinsic protein fluorescence was found to quench due to the formation drug-protein complex in case of CAF resulting a linear Stern-Volmer (SV) plot with K = 1.83 × 10 M.On the other hand, a positive deviation beyond [SDZ] ~0.15 mM is explained due to the formation of a fluorophore - quencher sphere with radius of 13.85 ± 1.80 Å that results almost one order of magnitude higher K (1.75 × 10 M). Molecular docking calculation also predicts relatively more stabilized complex of SDZ with LYS in comparison to CAF (ΔE ~ 3 kJ mol). Synchronous fluorescence results corresponding to Trp and Tyr residues as well as FTIR spectra in the amide I region of LYS confirms minimal deformation in the LYS secondary structure on adsorption to spherical NP surface. Although the nature of LYS-drug interaction remains invariant, the extent of quenching interaction as well as the drug binding ability is strongly modulated in presence of NPs. Further, the antibacterial activity of LYS in presence of the investigated drugs shows 9-14% upsurge with AuNP, in sharp contrast to ca. 31-34% decrease in AgNP.

Sulfonylurea Class of Antidiabetic Drugs Inhibit Acetylcholinesterase Activity: Unexplored Auxiliary Pharmacological Benefit toward Alzheimer’s Disease

“…= 14 ± 2 and 8 ± 2 nm, respectively, are synthesized and characterized following the procedure described elsewhere. 52 As can be seen from Figure 7, the activity of AChE, which was considerably lowered in the presence of 20 μM GLY, is enhanced in the presence of both Au and Ag NPs. The K m and V max values of AChE activity in the presence of 20 μM GLY in buffer (786 ± 19 μM and 747 ± 15.3 nM s −1 , respectively) further change to 269 ± 7.8 μM and 768 ± 11.9 nM s −1 in the presence of 1 mM AgNP.…”

“…Recently, nanostructured materials have found huge applications in diverse fields. , It is well documented that adsorption of enzymes on nanostructured solid support leads to enhanced performance in terms of activity. , The phenomenon of boosting the enzyme activity is attributed to various factors like the large surface area of nanomaterials and multipoint attachment of enzyme molecules to nanomaterials, resulting in a decrease in protein unfolding, a phenomenon that results in many diseases including neurodegenerative disorders . This further results in the improved stability of the enzyme attached to the nanoparticles (NPs) and, in turn, advances the enzyme–substrate interaction by avoiding the potential aggregation of the free enzyme.…”

Cannabidiol Inhibits Tau Aggregation In Vitro

“…To obtain the binding constants as well as the number of the binding sites of CBD on tau protein, Hill equation was used, where and are fluorescence intensities in the absence and presence of the quencher, respectively. In addition, is the binding constant, is the number of the binding sites of CBD on tau protein, and is the concentration of the ligand (CBD) [ 27 , 28 ].…”

“…where F 0 and F are fluorescence intensities in the absence and presence of the quencher, respectively. In addition, K b is the binding constant, n is the number of the binding sites of CBD on tau protein, and [L] is the concentration of the ligand (CBD) [27,28].…”

Combined computational and experimental studies on cysteine-sulfadiazine adduct formation

“…Although there are many studies on the interactions of SD with some compounds (cyclodextrins, glycine, leucine, aspartic acid, glutamic acid, arginine, human serum albumin, peptide amides, lysozyme, DNA, watersoluble proteins) [1][2][3][30][31][32][33][34][35], adduct formation between SD and CYS has not been addressed in the literature.…”