Structural basis for the formation of soy protein nanofibrils

Abstract

Identification of the peptide building blocks of soy protein nanofibrils provides new clues about the determinants of protein nanofibril morphology.

Protein nanofibrils and their use as building blocks of sustainable materials

“…5). [70][71][72][73] Beside their more evident curvature, these brils are typically also thinner and they have different nanomechanical properties than the "straight" type of brils with signicantly lower values of the persistence length and Young's modulus. 74,75 They also behave differently in the manufacturing of macroscopic, hierarchical materials, illustrating nicely that the nanoscale structure can dictate macroscale properties.…”

“…71,108 The link between hydrolysis and bril formation has been shown for several proteins. 72,73,103,[109][110][111] Notably, proteolytic cleavage of proteins is commonly observed for diseases-associated amyloid proteins. 21 The role of hydrolysis can be rationalized in the light of the length-dependence of the amyloid stability described above.…”

“…Another fascinating nding is the three different segments from soy proteins that constitute 'b-archs' motifs 114 that have obvious similarities with the molecular structures of protolaments. However, looking at all the examples, there are no obvious structural preferences of the segments in the native state as a- 73 helices, b-strands and random coil structures are all represented. There is also a variation on the positioning of the segments within the full-length sequences with both middle segments (e.g.…”

“…This assumption is strengthen by the fact that synthetic peptides corresponding to the core regions of soy bean PNFs formed long straight fibrils, while the full-length proteins mainly formed curved. 73 Moreover, the strong connection between the reaction conditions (pH, ionic strength, organic solvent, etc. ) and the morphology suggest that the intermolecular interactions are important and that worm-like structures may have a lower density of backbone hydrogen bonds.…”

“…(D) Soybean glycinin and b-conglycinin. The protein subunits have high structural similarity and peptides from different subunits are illustrated in the structure of b-conglycinin subunit b 73.…”