Molecular features of interaction involving hen egg white lysozyme immobilized on graphene oxide and the effect on activity

In-depth understanding of a nano-bio interface between lysozyme and Au NP-immobilized N-doped reduced graphene oxide 2-D scaffolds

“…7c reveals the upward curvature of the uorescence intensity, signifying the contribution of both static and dynamic factors. Bera et al 15 also observed similar results for the uorescence quenching of Lys in the presence of graphene oxide (GO) and deviation from the Stern-Volmer relation. It is also interesting to note that upon increasing the Au(0)-NrGO concentration from 50 to 200 mg mL À1 and 200 to 400 mg mL À1 , a two-fold decrease in quenching intensity was observed, while there was a much smaller decrease aer this concentration.…”

“…Thus, collectively, all the results illustrate that Lys favorably binds with the surface of Au(0)-NrGO, forming 2-D scaffolds, which results in an increase in the d H value. The surface of the native Lys contains a net positive charge 15,61 and Au(0)-NrGO is negatively charged, which provides the possibility of electrostatic interactions between them. Furthermore, other various interactions are possible, such as hydrophobic interactions, H-bonding between the O and N groups present in the Au(0)-NrGO sheet with the protein, and interactions between the gold molecules immobilized on the NrGO sheets and sulphur-containing amino acid residues present inside the Lys protein.…”

“…[12][13][14] Therefore, it is vital to understand protein interactions with NPs at the molecular level. 15 In the modern era, the potential of carbon-based nanomaterials has been demonstrated in numerous applications, especially in the biomedical eld. Graphene and its derivative graphene oxide (GO) have gained increasing attention due to their remarkable physicochemical properties, and have various applications in the elds of drug delivery, biomedical application, therapy, and sensing.…”

“…GO has an extremely large specic surface area, rich in oxygen-containing functional groups, which are responsible for its interaction with various proteins without further modication. 15,22 Many studies have addressed the interactions of proteins with GO, and results have shown a problem related to the signicant loss of protein structure and/or activity [23][24][25][26][27][28] due to the electrostatic interaction between the protein functional groups and GO or functionalized GO. On the other hand, in comparison to GO, when reduced graphene oxide (rGO) is used to conjugate proteins, a higher protein loading, higher activity and stability is observed.…”

Effect of gold nanoparticles on the structure and neuroprotective function of protein L-isoaspartyl methyltransferase (PIMT)

“…However, it is difficult to generalize as protein-NP interaction and the consequent conformational changes depend on the intrinsic properties of that particular protein 24 . Graphene oxide was found to have different effect on thermal (and storage) stability of a number of proteins, and with lysozyme, though there was no significant change in structure, the binding near the active site affected the flexibility of the surrounding residues and contributed to the reduction of the activity 44 . In the present study we find that among the three AuNSs, the largest, AuNS100 showed the maximum stabilization of the structure and anti-fibrillation activity of PIMT, whereas we had earlier reported that the same AuNS100 compromised the structure/function of a toxic protein (less than half the size of PIMT), Accessory cholera enterotoxin (Ace) of Vibrio cholera , but the smaller AuNS10 did not have much influence on the structure 45 .…”