Atomistic Modeling of Peptide Aggregation and β-Sheet Structuring in Corn Zein for Viscoelasticity

Abstract

The structure–function relationships of plant-based proteins that give rise to desirable texture attributes in order to mimic meat products are generally unknown. In particular, it is not clear how to engineer viscoelasticity to impart cohesiveness and proper mouthfeel; however, it is known that intermolecular β-sheet structures have the potential to enhance the viscoelastic property. Here, we investigated the propensity of selected peptide segments within common corn α-zein variants to maintain stable aggregates and β-sheet structures. Simulations on dimer systems showed that stability was influenced by the initial orientation and the presence of contiguous small hydrophobic residues. Simulations using eight-peptide β-sheet oligomers revealed that peptide sequences without proline had higher levels of β-sheet structuring. Additionally, we identified that sequences with a dimer hydrogen-bonding density of >22% tended to have a larger percent β-sheet conformation. These results contribute to understanding how the viscoelasticity of zein can be increased for use in plant-based meat analogues.

Formulation, Characterisation and Evaluation of the Antihypertensive Peptides, Isoleucine-Proline-Proline and Leucine-Lysine-Proline in Chitosan Nanoparticles Coated with Zein for Oral Drug Delivery

“…Zein and chitosan have isoelectric points of 6.2 and 6.8 [ 51 , 52 ], respectively, which may result in poor physical stability and dispersibility in neutral pH in aqueous systems, limiting the potential to produce efficient delivery systems. Zein is amphiphilic and has hydrophobic regions that degrade slowly by hydrolysis but can cause aggregation into colloidal particles [ 53 , 54 ]. A number of stabilisers have previously been used to help reduce aggregation of NP during lyophilisation, for example trehalose [ 55 , 56 ], sodium caseinate [ 57 ], lecithin and Pluronic F68 [ 58 ].…”

Technological interventions in improving the functionality of proteins during processing of meat analogs

“…The self-assembled zein networks had comparable rheological behavior to chicken breast, thus presenting an opportunity for zein in plant-based food structuring. The intermolecular β-sheet structure has the potential to improve viscoelasticity, hence improving cohesiveness and proper mouthfeel in the developed meat analogs ( 60 ). Erickson et al ( 60 ) proposed atomistic modeling of peptide aggregation and β-sheet structuring for improving the viscoelasticity of corn zein.…”

“…The intermolecular β-sheet structure has the potential to improve viscoelasticity, hence improving cohesiveness and proper mouthfeel in the developed meat analogs ( 60 ). Erickson et al ( 60 ) proposed atomistic modeling of peptide aggregation and β-sheet structuring for improving the viscoelasticity of corn zein. The authors observed that peptide sequences without proline had a higher level of β-sheet structuring.…”

Conformations of a highly expressed Z19 α-zein studied with AlphaFold2 and MD simulations

“…Only the hairpin model agreed with their CD-studies on commercial zein mixtures by giving increased β-sheet in more hydrophilic solvent. The study [48] focused on β-sheet propensities of peptide segments from the three most expressed α-zein clones αz19b1, αz19b3 (=cZ19C2) and αz22z1 found by Woo et al . The cZ19C2 peptides were from positions 9-19, 21-28, 75-90 and 148-157.…”