Structure, Immunogenicity, and IgE Cross-Reactivity among Walnut and Peanut Vicilin-Buried Peptides

Abstract

Vicilin-buried peptides (VBPs) from edible plants are derived from the N-terminal leader sequences (LSs) of seed storage proteins. VBPs are defined by a common α-hairpin fold mediated by conserved CxxxCx(10–14)CxxxC motifs. Here, peanut and walnut VBPs were characterized as potential mediators of both peanut/walnut allergenicity and cross-reactivity despite their low (∼17%) sequence identity. The structures of one peanut (AH1.1) and 3 walnut (JR2.1, JR2.2, JR2.3) VBPs were solved using solution NMR, revealing similar α-hairpin structures stabilized by disulfide bonds with high levels of surface similarity. Peptide microarrays identified several peptide sequences primarily on AH1.1 and JR2.1, which were recognized by peanut-, walnut-, and dual-allergic patient IgE, establishing these peanut and walnut VBPs as potential mediators of allergenicity and cross-reactivity. JR2.2 and JR2.3 displayed extreme resilience against endosomal digestion, potentially hindering epitope generation and likely contributing to their reduced allergic potential.

Design of glucono‐δ‐lactone‐induced pinto bean protein isolate/κ‐carrageenan mixed gels with various microstructures: fabrication, characterization, and release behavior

“…Sodium azide was added to PBI dispersion at a concentration of 50 mg.L −1 to avoid microbial growth. The pH of the PBI dispersion was then set to 8.90 ± 0.05 using NaOH (1.0 or 0.1 mol L −1 ), and the dispersion that was subsequently obtained was heated at 115–117 °C for 20 min 37,44,45 . Aqueous ethanolic (50%) curcumin (Cu) solution was incorporated into aggregated PBI dispersion (PBA) to adjust the final concentration of curcumin to 1.4 mg mL −1 (curcumin to protein ratio of 1:50 w/w).…”

“…Phytohemagglutinin is a lectin found in plants, especially certain legumes, with a molecular weight range of 16 to 30 kDa 35 . It has been documented that bean peptides have different biological properties, including antimicrobial, antioxidant, antithrombotic, and antihypertensive effects 37 . Despite several studies on the functional properties of PBI, only a few studies have been carried out to evaluate the gel‐forming capability of this protein 30,35,38 …”

“…31 The release characteristics of gel-like carriers are controlled directly by microstructure, and different microstructures for binary gels can be achieved by altering the concentration of polymers, polymer ratio, and gelation condition. 32 The incorporation of various polysaccharides into plant proteins, such as sugar beet pectin into soy protein, 33 wheat bran cellulose into soy protein, 34 mesona blumes polysaccharide into soy protein, 35 gellan gum into oat protein 36 and Basil seed gum into Kidney bean protein isolate, 37 expands the application of the polysaccharides and the proteins. Although the method for the fabrication of binary gels has been reported broadly, most of the studies have been related to the microstructure, texture, and sensory properties of binary gels.…”

“…35 It has been documented that bean peptides have different biological properties, including antimicrobial, antioxidant, antithrombotic, and antihypertensive effects. 37 Despite several studies on the functional properties of PBI, only a few studies have been carried out to evaluate the gel-forming capability of this protein. 30,35,38 Κ-Carrageenan, the major component of red seaweeds, belongs to the group of sulfated linear polysaccharides composed of repeated units of sulfated galactan.…”

Still SDAPing Along: 20 Years of the Structural Database of Allergenic Proteins

“…Allergens can have many diverse structures ( Figure 1B ) ( 33 – 37 ) with functional ( 38 ) or even “disordered” ( 39 ) regions that contain epitopes. One of the most important and distinguishing features of SDAP is the incorporation of structural data, through direct links to files in the Protein Database (PDB) or model structures made from suitable templates ( 34 , 36 ).…”