A fluorimetric study on the interaction between a Trp‐containing beta‐strand peptide and amphiphilic polymer‐coated gold nanoparticles

Abstract

Owing to the inevitability of nanoparticles encountering proteins/peptides in current bio-nano-medicine development, it is important to know how they interact with each other in vitro before developing in vivo applications. To this end, a model de novo β-sheet-forming peptide and typical biocompatible nanoparticles were selected to study thermodynamic aspects of their interactions via a fluorescence quenching method. The results showed that Pep11 and AuNPs spontaneously formed conjugates, mainly driven by a coulombic interaction with a binding affinity of ~ 0.1 µM(-1); the physical adsorption process was cooperative. These results deepen our quantitative understanding of nanoparticle-peptide interactions. The results may also be helpful in further nanoparticle-peptide hybrid nanofabrication and also useful for the application of nanoparticles in the treatment of amyloid diseases.

Interaction study on bovine serum albumin physically binding to silver nanoparticles: Evolution from discrete conjugates to protein coronas

“…Alternatively, the Hill equation (Eq-3) can be used to analyse the quenching data with more significant parameters ( Figure 3C). By summarizing the results at three different temperatures (298 K, 304 K and 310 K) in table 2, the phenomena that K q is correlated with but K a is inversely correlated with temperature proved that there was a static quenching, which indicates the BSA n -AP-AgNP should be initiated by the conjugate formation [20,27,28]. In addition, we can also get the Hill coefficient, n which describes the degree of cooperativity in ligand binding to a surface [39].…”

“…To further get the knowledge of how strong the physisorption is responsible for the robust BSA n -AP-AgNPs formation, and by making best use of the AgNPs as a good quencher for photoluminescence (PL) [36], we employed the fluorescence quenching method [20,27,28] to study thermodynamics of the current physisorption procedure. Figure 3A clearly shows the BSA's PL is more and more quenched with the increasing addition of AP-AgNPs.…”

“…For the fluorometric titration experiment, 0.9 mL solutions containing different BSA/AP-AgNP ratio numbers with a fixed final BSA concentration of 0.33 μM (Table 1) was prepared and incubated at different temperatures (298 K, 304 K and 310 K) for 60 min. Taking into account of the inner-filter effect (IFE) in the quenching process, all of the fluorescence intensities measured were corrected by using the following equation (Eq-1) according to the previously protocols [20,27,28].…”

“…With the aim to protein adsorption in aqueous buffer, the as-prepared AgNPs were then transferred into aqueous buffer by using the AP coating approach [20,[26][27][28]. The diameter of purified AP-AgNPs was determined to ~ 15.0 nm ( Figure 1B), which indicates that the organic/polymer coating layer has a thickness of ~ 4.3 nm.…”

Study on physisorption between G‐actin and amphiphilic polymer‐coated gold nanoparticles

“…AP coating has been considered as a universal approach to synthesize and stabilize NPs for a wide biomedical applications . After AP coating, AP–AuNPs normally can be used as model NPs with a monodispersed size distribution, and are ready for bioconjugation with robust stabilities, in addition to the above‐mentioned properties.…”