Amyloid-like aggregation of recombinant ß-lactoglobulin at pH 3.5 and 7.0: Is disulfide bond removal the key to fibrillation?
Int J Biol Macromol
; 242(Pt 2): 124855, 2023 Jul 01.
Article
en En
| MEDLINE
| ID: mdl-37187417
ABSTRACT
Functional nanofibrils from globular proteins are usually formed by heating for several hours at pH 2.0, which induces acidic hydrolysis and consecutive self-association. The functional properties of these micro-metre-long anisotropic structures are promising for biodegradable biomaterials and food applications, but their stability at pH > 2.0 is low. The results presented here show that modified ß-lactoglobulin can also form nanofibrils by heating at neutral pH without prior acidic hydrolysis; the key is removing covalent disulfide bonds via precision fermentation. The aggregation behaviour of various recombinant ß-lactoglobulin variants was systemically studied at pH 3.5 and 7.0. The suppression of intra- and intermolecular disulfide bonds by eliminating one to three out of the five cysteines makes the non-covalent interactions more prevalent and allow for structural rearrangement. This stimulated the linear growth of worm-like aggregates. Full elimination of all five cysteines led to the transformation of worm-like aggregates into actual fibril structures (several hundreds of nanometres long) at pH 7.0. This understanding of the role of cysteine in protein-protein interactions will help to identify proteins and protein modifications to form functional aggregates at neutral pH.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Asunto principal:
Amiloide
/
Lactoglobulinas
Idioma:
En
Revista:
Int J Biol Macromol
Año:
2023
Tipo del documento:
Article
País de afiliación:
Países Bajos