Interactions of Surface-Functionalized Starch Nanoparticles with Pepsin and Trypsin in Simulated Gastrointestinal Fluids

Abstract

Nanoparticles (NPs) can form a protein corona (PC) with proteins in biological fluids. We examined whether starch nanoparticles (SNPs) form a PC and interact with digestive enzymes in simulated gastric and intestinal fluids. We investigated the adsorption of pepsin and trypsin on unmodified, carboxyl-, and amino-modified SNPs (SNPs, COOH-SNPs, and NH2-SNPs, respectively). Quartz crystal microbalance data showed that a tight and irreversible pepsin corona formed on the NH2-SNPs, pepsin had little or no binding to the SNPs and COOH-SNPs, and trypsin had weak binding to all three kinds of NPs. Dynamic light scattering data showed that pepsin significantly increased the size of the NH2-SNPs from 120 ± 2.6 to 203 ± 12.2 nm and decreased their surface potential from 23.2 ± 1.0 to 12.7 ± 0.2 mV. NH2-SNPs could induce the fluorescence quenching of pepsin and change its secondary structures without affecting its activity.

Impact of Heat Treatment on the Structure and Properties of the Plant Protein Corona Formed around TiO2 Nanoparticles

“…When the nanoparticles were washed, there was a slight decrease in the mass of adsorbed protein (Δ m 1 ), which indicates that some of the protein was in a soft layer. However, the majority of the proteins remained attached after washing (Δ m 2 ), which suggests that they were in a hard layer. , …”

“…However, the majority of the proteins remained attached after washing (Δm 2 ), which suggests that they were in a hard layer. 2,40 The values of Δm 1 and Δm 2 for the different heat-treated proteins are shown in Table 1. The mass of protein in the hard and soft layers of the protein coronas depended strongly on protein type and heat treatment.…”

“…The size distributions and average diameters of the samples were measured using a dynamic light scattering instrument (Malvern Instruments Ltd., Malvern, U.K.). 27 The heat-treated proteins were diluted to a concentration of 1 mg/mL. The samples were then placed in a 1 cm optical cuvette and equilibrated at 25 ± 1 °C prior to analysis.…”

“…During the manufacturing process, foods undergo various types of thermal processing operations, which can alter the structure, aggregation state, and functionality of proteins . For instance, high-temperature heat treatment can disrupt the internal disulfide bonds of rice glutenin aggregates and induce protein conformational changes, thereby reducing the size of protein and increasing the surface potential of protein. , Structural and conformational changes induced by heat treatment of album protein isolates enhanced protein functional properties and in vitro digestibility. We therefore hypothesized that thermal treatments of plant proteins might alter their ability to form protein coronas around inorganic nanoparticles, which could alter their behavior in foods and the gastrointestinal tract.…”

Interaction of Carbon Dots from Grilled Spanish Mackerel with Human Serum Albumin, γ-Globulin and Fibrinogen

“…Synchronous fluorescence spectroscopy can provide instruction about the biomolecular microenvironment around the protein or amino acid fluorophores. The feature information of tyrosine (Tyr) and tryptophan (Trp) can be monitored by inputting a fixed ∆λ value of 15 or 60 nm between the two monochromators [38,39]. With the concentration increase of FCDs, the synchronous fluorescence intensity of all amino acid residues of the three proteins decreased gradually.…”