Disulfide Bond Formation Research Articles

Disulfide-driven Pore Functionalization of Metal-organic Frameworks.

Post-synthetic modification (PSM) imparts additional functionality to metal-organic frameworks (MOFs) that is often difficult to access using solvothermal synthesis. As such, expanding the repertory of PSM reactions available to the practitioner is of increased importance for the generation of materials tailored for desired applications. Herein, we describe a method for the protecting group-free installation of diverse functional groups within the pores of a MIL-53(Al) analogue via disulfide bond formation. The majority of the reactions proceed with thiol-to-disulfide conversions ranging from high to nearly quantitative. The disulfide bonds are stable in various solvents and can be cleaved in the presence of a reducing agent.

Self-assembly regulation of montmorillonite nanosheet for Pb(II) removal from aqueous solution

L-cysteine (Lcys) induced the self-assembly of montmorillonite nanosheets (MMTNS), creating a three-dimensional structured adsorbent with high adsorption capacity for Pb(II). Lcys was grafted onto the edge of MMTNS by hydrogen-bonding and then formed disulfide bonds (–S–S–) under the oxidation of H2O2 to form MMTNS-Lcys adsorbent. This technique maintains the exposed adsorption sites of MMTNS and resolves the challenge of nanosheet separation from water. MMTNS-Lcys possessed a large specific surface area (73.95 m2 g−1) and pore volume (0.1124 cm3 g−1), exhibiting outstanding adsorption performance for Pb(II), The adsorption process is consistent with the Pseudo-first-order kinetic and Langmuir isotherm models, indicating the monolayer adsorption of Pb(II) on the homogeneous surface of the MMTNS-Lcys adsorbent, with a maximum adsorption capacity of 46.92 mg/g (C0 = 80 mg/L, M = 0.5 g/L, T = 25 °C, pH = 6). These findings offer valuable insights for the design and development of future adsorbent materials.

Interaction with wheat starch affect the aggregation behavior and digestibility of gluten proteins

Understanding the interplay between gluten and wheat starch is crucial for elucidating the digestibility mechanism of gluten in wheat-based products. However, this mechanism remains under-investigated. This study sought to elucidate the influence of starch-induced protein structural modifications on gluten digestion. Our findings revealed that starch considerably enhanced gluten digestion. In the presence of starch, gluten protein digestibility increased from 10.91 % (in the control group with a gluten-to-starch ratio of 1:0) to 14.40 % (in the complex with a gluten-to-corn starch ratio of 1:1). The diminished gluten protein digestibility due to starch may be ascribed to modifications in protein configuration and aggregation behavior. Morphological studies suggested that starch not only functioned as filler particles but also diluted the gluten matrix. A protein network assessment further affirmed that both the junction density and branching rate of gluten proteins decreased notably by 29.9 % and 25.1 %, respectively. Conversely, lacunarity increased by 1.92-fold, compromising the cohesiveness and connectivity of the gluten matrix. Elevated starch concentrations suppressed the formation of disulfide bonds, impeding gluten protein aggregation. Concurrently, gluten-starch interactions were governed by hydrogen bonds and hydrophobic associations. In summary, starch augmented gluten protein digestibility by curtailing their polymerization. This revelation might offer novel perspectives on optimizing gluten protein digestion and utilization.

Microbial transglutaminase promotes cross-linking for enhancing gelation of myofibrillar protein in frozen Litopenaeus vannamei through deamination reaction

In this paper, the effects of different microbial transglutaminase (mTGase) treatments (0–0.5% w/w) on the structural and functional characteristics of frozen shrimp (Litopenaeus vannamei) were investigated to explore the changes in myofibrillar protein (MP) during the catalytic process of mTGase, and further enhance the gel properties of shrimp surimi products. Fourier transform infrared spectroscopy showed that mTGase treatment caused a shift from α-helix to β-turn and β-sheet in the secondary structure of the protein, while chemical force results indicated that moderate addition of enzyme could promote the formation of disulfide bonds in the gel system, contributing to the formation of a stable three-dimensional spatial structure. These structural changes led to a significant increase in gel strength, WHC and storage modulus (G′) after mTGase-induced protein gelation, resulting in an increase in the solid properties of the gel; and the relaxation time T22 was significantly shortened, indicating a gradual decrease in water freedom in the protein gel network. In addition, scanning electron microscopy results showed that the gel with 0.4% mTGase had a denser network structure and more uniform pores. Simultaneously, mTGase facilitated the reduction of free amino groups through deamination reaction, resulting in an elevated cross-linking degree and a reduced hydrolysis rate of pepsin. The above results indicated that appropriate mTGase treatment could improve the structure and functional properties of shrimp, benefit the quality of shrimp surimi products, and provide some references for the highly processed frozen Litopenaeus vannamei.

One-step production of fully biotinylated and glycosylated human Fc gamma receptors.

Initiating and regulating humoral immunity, Fc gamma receptors (FcγRs) have been identified both as therapeutics and as drug targets, and thus production of biologically active FcγRs is highly demanded for biopharmaceutical development. Focusing on low-affinity FcγRs IIA (131H/R allotypes), IIB, and IIIA (176F/V), this study used human 293-F cells to achieve correct post-translational modifications (PTMs) including biotinylation, N-glycosylation, and disulfides. Approaches involving co-expression of FcγR-AviTag and Escherichia coli biotin ligase BirA, endoplasmic reticulum retention, stable and transient transfections, and optimization of transgene ratio were investigated. Protein electrophoresis under reducing and non-reducing conditions, enzymatic deglycosylation, streptavidin pull-down assays, and binding kinetic analysis collectively indicated that the produced FcγR ectodomains were fully biotinylated, N-glycosylated, had formed disulfide bond, and exhibited expected binding affinities toward IgG1 trastuzumab and its Fc mutants. A clear trade-off between production yield and PTM quality was also observed. Achieving multiple types of PTMs completely by one-step cell culture should have applications for the production of a variety of complex proteins of biomedical importance.

Nuclear factor kappa B expression in non-small cell lung cancer

In this mini-review, we discuss the role of NF-κB, a proinflammatory transcription factor, in the expression of genes involved in inflammation, proliferation, and apoptosis pathways, and link it with prognosis of various human cancers, particularly non-small cell lung cancer (NSCLC). We and others have shown that NF-κB activity can be impacted by post-translational S-glutathionylation through reversible formation of a mixed disulfide bond between its cysteine residues and glutathione (GSH). Clinical data analysis showed that high expression of NF-κB correlated with shorter overall survival (OS) in NSCLC patients, suggesting a tumor promotion function for NF-κB. Moreover, NF-κB expression was associated with tumor stage, lymph node metastasis, and 5-year OS in these patients. NF-κB was over-expressed in the cytoplasm of tumor tissue compared to adjacent normal tissues. S-glutathionylation of NF-κB caused negative regulation by interfering with DNA binding activities of NF-κB subunits. In response to oxidants, S-glutathionylation of NF-κB also correlated with enhanced lung inflammation. Thus, S-glutathionylation is an important contributor to NF-κB regulation and clinical results highlight the importance of NF-κB in NSCLC, where NF-κB levels are associated with unfavorable prognosis.

Extracellular calcium functions as a molecular glue for transmembrane helices to activate the scramblase Xkr4

The “eat me” signal, phosphatidylserine is exposed on the surface of dying cells by phospholipid scrambling. Previously, we showed that the Xkr family protein Xkr4 is activated by caspase-mediated cleavage and binding of the XRCC4 fragment. Here, we show that extracellular calcium is an additional factor needed to activate Xkr4. The constitutively active mutant of Xkr4 is found to induce phospholipid scrambling in an extracellular, but not intracellular, calcium-dependent manner. Importantly, other Xkr family members also require extracellular calcium for activation. Alanine scanning shows that D123 and D127 of TM1 and E310 of TM3 coordinate calcium binding. Moreover, lysine scanning demonstrates that the E310K mutation-mediated salt bridge between TM1 and TM3 bypasses the requirement of calcium. Cysteine scanning proves that disulfide bond formation between TM1 and TM3 also activates phospholipid scrambling without calcium. Collectively, this study shows that extracellular calcium functions as a molecular glue for TM1 and TM3 of Xkr proteins for activation, thus demonstrating a regulatory mechanism for multi-transmembrane region-containing proteins.

Azodicarboxylate‐Mediated Peptide Cyclisation: Application to Disulfide Bond Formation in Solution and Solid Phase

AbstractCyclic peptides are important molecules, playing key roles in protein architecture, as chemical probes, and increasingly as crucial structural elements of clinically‐useful therapeutics. Herein we report methodology using azodicarboxylates as efficient reagents for the facile synthesis of cyclic peptides through a disulfide bridge. The utility of this approach in both solution and solid‐phase, and compatibility with common amino acid side chain functionalities is demonstrated, resulting in cyclic peptides in good yield and purity. This approach has significant potential application for synthesis of molecules of biological or therapeutic significance.

Effect of sheeting stress and heating on the molecular chain structure, size, and conformation of gluten proteins during noodle processing

In this paper, the changes in molecular structure, size distribution, and conformation of gluten induced by the mechanical stress during sheeting and the heating effect during cooking of noodles were investigated by atomic force microscopy (AFM), X-ray scattering (SAXS), and size-exclusion chromatography multi-angle laser light scattering (SEC-MALLS). AFM results showed that the height and width of gluten molecular chains were decreased after calendering and increased post-cooking. Calendering reduced the molecular size and compacted the gluten network (increased Dm). The SDS extractable gluten components showed a quasi-spherical chain conformation but gradually changed to a random coil conformation due to heating. According to SEC-MALLS profiles, calendering and appropriate heating (4 min) promoted the homogeneity of molecular mass of glutenin polymer. The mechanical depolymerization and the heat-promoted polymerization of gluten could be due to the breakage and formation of disulfide bonds and the interconversion of sulfhydryl groups.

Identification and functional analysis of endoplasmic reticulum oxidoreductase 1 (ERO1) from the green mud crab Scylla paramamosain: The first evidence of ERO1 involved in invertebrate immune response.

Endoplasmic reticulum oxidoreductase 1 (ERO1) is an important mediator in regulating disulfide bond formation and maintaining endoplasmic reticulum homeostasis. Its activity is transcriptionally regulated by the unfolded protein response (UPR) in the endoplasmic reticulum, which is known to be essential in immunity. However, whether ERO1 is involved in innate immunity in invertebrates remains unclear. In the present study, two subtypes of ERO1 from Scylla paramamosain were first identified and characterized. Sequence analysis revealed the conserved ERO1 domain and the oxidative capacity assay verified the oxidative capacity of SpERO1 recombinant protein. Moreover, SpERO1s were found to be ubiquitously expressed in all the tested tissues, with the highest expression observed in hemocytes. Two SpERO1s exhibited distinct expression patterns in response to Vibrio alginolyticus and White Spot Syndrome Virus (WSSV). Importantly, the downregulation of the expression of immune factors upon bacterial challenge in SpERO1-silenced crabs was observed. These results provided an initial foundation for further investigations into the role of ERO1 in the innate immunity of invertebrates.

Biochemical analysis of Komagataella phaffii oxidative folding proposes novel regulatory mechanisms of disulfide bond formation in yeast

Oxidative protein folding in the endoplasmic reticulum (ER) is driven mainly by protein disulfide isomerase PDI and oxidoreductin Ero1. Their activity is tightly regulated and interconnected with the unfolded protein response (UPR). The mechanisms of disulfide bond formation have mainly been studied in human or in the yeast Saccharomyces cerevisiae. Here we analyze the kinetics of disulfide bond formation in the non-conventional yeast Komagataella phaffii, a common host for the production of recombinant secretory proteins. Surprisingly, we found significant differences with both the human and S. cerevisiae systems. Specifically, we report an inactive disulfide linked complex formed by K. phaffii Ero1 and Pdi1, similarly to the human orthologs, but not described in yeast before. Furthermore, we show how the interaction between K. phaffii Pdi1 and Ero1 is unaffected by the introduction of unfolded substrate into the system. This is drastically opposed to the previously observed behavior of the human pathway, suggesting a different regulation of the UPR and/or possibly different interaction mechanics between K. phaffii Pdi1 and Ero1.

Study on the mechanism of structure modification of amylopectin co-crystalized by sodium chloride to promote disulfide bond formation of alkali-soluble glutenin

Strength and stiffness are the main characteristics of high-quality dough products. As one of the key components to endow those functions to noodles, formation of disulfide bonds in alkali-soluble glutenin (ASG) is very important. Interaction of ASG and co-crystalized wheat amylopectin with NaCl could prompt formation of disulfide bonds of ASG and its mechanism was deduced in the paper. The results showed that the disulfide bonds contents of ASG were increased significantly by interaction with co-crystalized wheat amylopectin. The co-crystalized wheat amylopectin with 2% NaCl for 24 h at 30 °C was distinguished by the Mn distribution of 0.55–0.95 × 106 g/mol, more chains with 18∼24 glucose residues being grafted from chains of 4∼7 glucose residues during the eutectic process, presence of the weak resonance enhancement at 96.5 ppm, molecular aggregate diameter less than 120 μm, and only one of X-diffraction angles 2θ at 20.2°. In the process of interaction, Qβ, Qδ, Yγ, Yε of ASG and C1, C6 of what amylopectin involved in the formation of disulfide bond, the contents of intermolecular β-sheet decreased and those of intra-molecular aggregation extended β-sheet and random coils increased. The peak melting temperature and melting enthalpy of the mixture decreased significantly after co-crystallized wheat amylopectin interacted with the ASG. Co-crystalized wheat amylopectin with NaCl can be used as a reinforcing agent of wheat flour.

A novel variable power microwave (VPM) drying technology for lowering energy consumption and improving the in vitro protein digestibility of black solider fly larvae

In this study, a novel variable power microwave (VPM) drying process that can automatically and continuously adjust microwave power according to temperature feedback was developed to dry black soldier fly larvae (BSFL). The influence of VPM and constant power microwave (CPM) drying on the drying time, energy consumption, and product quality of BSFL and the potential relationship between BSFL quality and microstructural properties were investigated. The results showed that VPM drying could reduce 17.14% ∼ 27.50% of the drying time and 3.37% ∼ 12.24% of the energy consumption compared with CPM drying. BSFL protein produced by VPM drying exhibited higher digestibility. VPM drying decreased the formation of β-sheets and disulfide bonds within the protein, reducing the aggregation of protein molecules. Scanning electron microscopy and differential scanning calorimetry analysis also demonstrated that VPM-dried BSFL products had smaller protein particle sizes and less protein denaturation. Industrial relevanceVPM drying can reduce energy consumption while improving BSFL drying efficiency and help to maintain the quality of dried products. The control system that can adjust the microwave power in real time according to the temperature feedback can be easily applied to the continuous tunnel microwave drying equipment widely used in the food industry to realize large-scale VPM drying of insects. The results obtained in this study can help to improve insect-based product quality by using VPM drying and provide technical support for edible insects as an alternative protein source in the future.

Design of an alternate antibody fragment format that can be produced in the cytoplasm of Escherichia coli

With increased accessibility and tissue penetration, smaller antibody formats such as antibody fragments (Fab) and single chain variable fragments (scFv) show potential as effective and low-cost choices to full-length antibodies. These formats derived from the modular architecture of antibodies could prove to be game changers for certain therapeutic and diagnostic applications. Microbial hosts have shown tremendous promise as production hosts for antibody fragment formats. However, low target protein yields coupled with the complexity of protein folding result in production limitations. Here, we report an alternative antibody fragment format ‘FabH3’ designed to overcome some key bottlenecks associated with the folding and production of Fabs. The FabH3 molecule is based on the Fab format with the constant domains replaced by engineered immunoglobulin G1 (IgG1) CH3 domains capable of heterodimerization based on the electrostatic steering approach. We show that this alternative antibody fragment format can be efficiently produced in the cytoplasm of E. coli using the catalyzed disulfide-bond formation system (CyDisCo) in a natively folded state with higher soluble yields than its Fab counterpart and a comparable binding affinity against the target antigen.

Preparation and Properties of High-Soluble Wheat Gluten Protein Based Meat Analogues.

Wheat gluten protein (WGP) has poor solubility and does not easily form fibrous structures, the meat analogues, prepared from it, have unsatisfactory texture properties and poor water holding capacity. Our previous work indicated that pH-shifting combined with heat treatment can significantly improve the solubility and emulsibility of WGP. Therefore, in this work, WGP was treated by pH-cycling (m-WGP) to improve the solubility and then applied in the preparation of meat analogues by high moisture extrusion. The results indicated that the addition of m-WGP significantly improved the texture characteristics and water holding capacity (282.4%) of the extrudates and made the extrudates show a tighter organizational structure according to the SEM images. Additionally, MRI analysis showed that the addition of m-WGP resulted in a more uniform moisture distribution in the extrudate. And the free sulfhydryl group result showed that the addition of m-WGP significantly increased the free sulfhydryl group content, which was beneficial to the formation of disulfide bonds to enhance the tissue structure. When the addition content of m-WGP was 10%, the gluten extrudate exhibited good water holding capacity and uniform moisture distribution, but the excessive hardness and chewiness were not suitable for simulating meat. When the addition content of m-WGP reached 50%, the gluten extrudate has the closest textural characteristics to commercial plant-based meat and real meat, with the potential to be used as a raw material to simulate meat. Accordingly, this work improves the processing properties of WGP and explores plant-based ingredients for meat analogues. This article is protected by copyright. All rights reserved.

Thermoresponsive Poly(N,N'-dimethylacrylamide)-Based Diblock Copolymer Worm Gels via RAFT Solution Polymerization: Synthesis, Characterization, and Cell Biology Applications.

RAFT solution polymerization is used to polymerize 2-hydroxypropyl methacrylate (HPMA). The resulting PHPMA precursor is then chain-extended using N,N'-dimethylacrylamide (DMAC) to produce a series of thermoresponsive PHPMA-PDMAC diblock copolymers. Such amphiphilic copolymers can be directly dispersed in ice-cold water and self-assembled at 20 °C to form spheres, worms, or vesicles depending on their copolymer composition. Construction of a pseudo-phase diagram is required to identify the pure worm phase, which corresponds to a rather narrow range of PDMAC DPs. Such worms form soft, free-standing gels in aqueous solution at around ambient temperature. Rheology studies confirm the thermoresponsive nature of such worms, which undergo a reversible worm-to-sphere on cooling below ambient temperature. This morphological transition leads to in situ degelation, and variable temperature 1H NMR studies indicate a higher degree of (partial) hydration for the weakly hydrophobic PHPMA chains at lower temperatures. The trithiocarbonate end-group located at the end of each PDMAC chain can be removed by treatment with excess hydrazine. The resulting terminal secondary thiol group can form disulfide bonds via coupling, which produces PHPMA-PDMAC-PHPMA triblock copolymer chains. Alternatively, this reactive thiol group can be used for conjugation reactions. A PHPMA141-PDMAC36 worm gel was used to store human mesenchymal stem cells (MSCs) for up to three weeks at 37 °C. MSCs retrieved from this gel subsequently underwent proliferation and maintained their ability to differentiate into osteoblastic cells.

Self-Assembly of Platelet Lysates Proteins into Microparticles by Unnatural Disulfide Bonds for Bottom-up Tissue Engineering.

There is a demand to design microparticles holding surface topographies while presenting inherent bioactive cues for applications in the biomedical and biotechnological fields. Using the pool of proteins present in human-derived platelet lysates (PL), it is reported the production of protein-based microparticles via a simple and cost-effective method, exploring the prone redox behavior of cysteine (-SH) amino acid residues. The forced formation of new intermolecular disulfide bonds results in the precipitation of the proteins as spherical, pompon-like microparticles with adjustable sizes (15-50μm in diameter) and surface topography consisting of grooves and ridges. These PL microparticles exhibit extraordinary cytocompatibility, allowing cell-guided micro-aggregates to form, while also working as injectable systems for cell support. Early studies also suggests that the surface topography provided by these PL microparticles can support osteogenic behavior. Consequently, these PL microparticles may find use to create live tissues via bottom-up procedures or injectable tissue-defect fillers, particularly for bone regeneration, with the prospect of working under xeno-free conditions. This article is protected by copyright. All rights reserved.

Tropolones and Thailandepsin B as Lead-like Natural Compounds in the Development of Potent and Selective Histone Deacetylase Inhibitors.

Tropolone and thailandepsin B are naturally occurring substances that are primarily isolated from fungi and plants, although they can also be found in certain bacteria. Tropolones belong to an important class of aromatic compounds with a seven-membered nonbenzenoid ring structure. Thailandepsins are a group of natural products that were initially discovered in the culture broth of the Gram-negative bacterium Burkholderia thailandensis. Tropolonebased structures have been identified in over 200 natural compounds, ranging from simple tropolone derivatives to complex multicyclic systems like pycnidione and pyrerubrine A. These natural compounds exhibit a diverse range of pharmacological effects, including antibacterial, antifungal, insecticidal, phytotoxic, anti-inflammatory, antimitotic, anti-diabetic, enzyme inhibitory, anticancer, cytoprotective, and ROS scavenging properties. It is worth noting that thujaplicane, a compound similar to tropolone, displays all of the listed biological activities except for antimitotic action, which has only been observed in one natural tropolone compound, colchicine. Tropolone can be synthesized from commercially available seven-membered rings or derived through various cyclization and cycloaddition reactions. Thailandepsin B, on the other hand, can be synthesized by macro-lactonization of the corresponding secoacid, followed by the formation of internal disulfide bonds. It is important to mention that thailandepsin B exhibits different selective inhibition profiles compared to FK228. We investigated the HDAC inhibitory activity of the Tropolones and Thailandepsin B and discussed the biosynthesis of the naturally occurring compounds and their synthetic scheme. It has been observed that Tropolone derivatives act as isoenzyme-selective inhibitors of proven anticancer drug targets, histone deacetylases (HDACs). Some monosubstituted tropolones show remarkable levels of selectivity for HDAC2 and strongly inhibit the growth of T-lymphocyte cell lines. And Thailandepsins have different selective inhibition profiles than FK228. They exhibit comparable inhibitory activities to FK228 against human HDAC1, HDAC2, HDAC3, HDAC6, HDAC7, and HDAC9, but less potent inhibitory activities than FK228 toward HDAC4 and HDAC8, the latter of which may be useful. Thailandepsins possess potent cytotoxic activities toward some types of cell lines.

PDIA3 modulates genomic response to 1,25-dihydroxyvitamin D3 in squamous cell carcinoma of the skin

An active form of vitamin D3 (1,25-dihydroxyvitamin D3) acts through vitamin D receptor (VDR) initiating genomic response, but several studies described also non-genomic actions of 1,25-dihydroxyvitamin D3, implying the role of PDIA3 in the process. PDIA3 is a membrane-associated disulfide isomerase involved in disulfide bond formation, protein folding, and remodeling. Here, we used a transcriptome-based approach to identify changes in expression profiles in PDIA3-deficient squamous cell carcinoma line A431 after 1,25-dihydroxyvitamin D3 treatment. PDIA3 knockout led to changes in the expression of more than 2000 genes and modulated proliferation, cell cycle, and mobility of cells; suggesting an important regulatory role of PDIA3. PDIA3-deficient cells showed increased sensitivity to 1,25-dihydroxyvitamin D3, which led to decrease migration. 1,25-dihydroxyvitamin D3 treatment altered also genes expression profile of A431ΔPDIA3 in comparison to A431WT cells, indicating the existence of PDIA3-dependent genes. Interestingly, classic targets of VDR, including CAMP (Cathelicidin Antimicrobial Peptide), TRPV6 (Transient Receptor Potential Cation Channel Subfamily V Member 6), were regulated differently by 1,25-dihydroxyvitamin D3, in A431ΔPDIA3. Deletion of PDIA3 impaired 1,25-dihydroxyvitamin D3-response of genes, such as PTGS2, MMP12, and FOCAD, which were identified as PDIA3-dependent. Additionally, response to 1,25-dihydroxyvitamin D3 in cancerous A431 cells differed from immortalized HaCaT keratinocytes, used as non-cancerous control. Finally, silencing of PDIA3 and 1,25-dihydroxyvitamin D3, at least partially reverse the expression of cancer-related genes in A431 cells, thus targeting PDIA3 and use of 1,25-dihydroxyvitamin D3 could be considered in a prevention and therapy of the skin cancer. Taken together, PDIA3 has a strong impact on gene expression and physiology, including genomic response to 1,25-dihydroxyvitamin D3.

Effects of Various Types of Vacuum Cold Plasma Treatment on the Chemical and Functional Properties of Whey Protein Isolate with a Focus on Interfacial Properties

Vacuum cold plasma (VCP), a novel non-thermal processing technology used to modify the physicochemical properties and functionalities of food materials, was applied to whey protein isolate (WPI). The treatment affects the protein chemistry and, as a result, leads to differences in the behavior in solution and at interfaces. To minimize the undesirable effects of high oxidation and to increase the effectiveness of reactive species, the VCP treatment was applied at low pressure using different types of gases (air, combination of argon and air, and sulfur hexafluoride (SF6)). The treatment led to a decrease in the sulfur content and an increase in the carbonyl content, evidenced by oxidation reactions and enhanced disulfide bond formation, as well as cross-linking of protein molecules. Fluorescence-based indicators suggest that the hydrophobicity of the proteins as well as their aggregation increase after VCP treatment with an argon–air gas mixture; however, it decreases after VCP treatments with air and SF6. The chemical modifications further lead to changes in the pH of aqueous WPI solutions, as well as the average size and ζ-potential of WPI aggregates. Moreover, the dynamic surface tension, surface dilational elasticity, and the thickness of the WPI adsorption layers at the air/water interface depend on the VCP type. SF6 plasma treatment leads to a significant decrease in pH and an increase in the ζ-potential, and consequently to a significant increase in the aggregate size. The dynamic surface tension as well as the adsorption rates increase after SF6VCP treatment, but decrease after air–VCP and argon–air–VCP treatments. The adsorbed WPI aggregates form strong viscoelastic interfacial layers, the thickness of which depends on the type of VCP treatment.