Peptides are Building Blocks of Heat-Induced Fibrillar Protein Aggregates of β-Lactoglobulin Formed at pH 2

Akkermans, C.; Venema, Paul; Goot, Atze Jan van der; Gruppen, Harry; Bakx, Edwin J.; Boom, R.M.; Linden, Erik van der

doi:10.1021/bm7014224

Cited by 252 publications

(293 citation statements)

References 30 publications

Supporting

Mentioning

252

Contrasting

Order By: Relevance

“…The whey protein β-lactoglobulin forms amyloid-like fibrils under several different conditions, including high concentrations of urea (20), in the presence of alcohols (21), and at low pH and elevated temperature (5,22). At low pH and high temperature, the fibrillation proceeds through hydrolysis of the protein into smaller peptide fragments and some of these peptides spontaneously assemble into PNFs (23). In the current study, we used whey protein isolate (WPI) as starting material because it gives us access to large amounts of Significance Protein nanofibrils formed by self-assembly have emerged as a promising foundation for the design of bio-based materials with enhanced mechanical properties or new functionality.…”

Section: Resultsmentioning

confidence: 99%

Flow-assisted assembly of nanostructured protein microfibers

Kamada

Mittal

Söderberg

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

115

View full text Add to dashboard Cite

Some of the most remarkable materials in nature are made from proteins. The properties of these materials are closely connected to the hierarchical assembly of the protein building blocks. In this perspective, amyloid-like protein nanofibrils (PNFs) have emerged as a promising foundation for the synthesis of novel bio-based materials for a variety of applications. Whereas recent advances have revealed the molecular structure of PNFs, the mechanisms associated with fibril-fibril interactions and their assembly into macroscale structures remain largely unexplored. Here, we show that whey PNFs can be assembled into microfibers using a flow-focusing approach and without the addition of plasticizers or cross-linkers. Microfocus small-angle X-ray scattering allows us to monitor the fibril orientation in the microchannel and compare the assembly processes of PNFs of distinct morphologies. We find that the strongest fiber is obtained with a sufficient balance between ordered nanostructure and fibril entanglement. The results provide insights in the behavior of protein nanostructures under laminar flow conditions and their assembly mechanism into hierarchical macroscopic structures.protein nanofibrils | amyloid | hierarchical assembly | flow focusing | small-angle X-ray scattering P roteins are widely used in nature to create high-performance materials that can have both extraordinary mechanical properties (similar to muscles, silks) and sophisticated functionalities (e.g., adhesion, biological signaling) (1). The characteristics of these materials are intimately connected to the hierarchical assembly of the protein building blocks with well-defined organization at all structural levels (2). Improved knowledge about how to control the assembly of protein molecules into higher-order structures would open the possibilities to create novel bio-based materials for a variety of applications. In this perspective, the ability of protein molecules to undergo nonnative self-assembly into protein nanofibrils (PNFs) with highly organized supramolecular structures is of significant interest (3). The formation of PNFs was initially observed in association with diseases, such as Alzheimer's and Parkinson's diseases, and type II diabetes, where human organs are impaired by fibrous protein inclusions referred to as amyloid (4). However, several non-disease-related proteins have also been shown to form amyloid-like fibrils, e.g., the bovine whey protein β-lactoglobulin (5), hen-egg lysozyme (6), and soybean proteins (7). The unique fibrous structures of PNFs have the potential for being the building block of protein-based nanomaterials and to be used as scaffolds for applications such as tissue engineering, drug delivery systems, and biosensors (3). PNFs are characterized by intermolecular β-sheet structures, where the peptide backbones are oriented perpendicularly to the fibril axis and connected through a network of hydrogen bonds (4,8). This provides them with stiffness equivalent to silk and strength comparable to steel (2, 8). Moreo...

show abstract

Section: Resultsmentioning

confidence: 99%

Flow-assisted assembly of nanostructured protein microfibers

Kamada

Mittal

Söderberg

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

115

View full text Add to dashboard Cite

show abstract

“…[1][2][3][4] We showed previously that the fibrils formed under these conditions consist of peptides originating from intact β-lactoglobulin molecules. 5 These peptides were formed due to acid hydrolysis of the bonds between aspartic acid residues and any other amino acid residue. The molecules inside these fibrils are held together by intermolecular β-sheets.…”

Section: Introductionmentioning

confidence: 99%

Enzyme-Induced Formation of β-Lactoglobulin Fibrils by AspN Endoproteinase

et al. 2008

Self Cite

View full text Add to dashboard Cite

This paper describes a low temperature, enzymatic route to induce fibrillar structures in a protein solution. The route comprises two steps. First, β-lactoglobulin was hydrolyzed into peptides at pH 8 and 37°C with the enzyme AspN endoproteinase, which resulted in the formation of random aggregates. After hydrolysis, the pH was lowered to 2. As a result, long fibrillar aggregates were formed which was observed using transmission electron microscopy and Thioflavin T fluorescence measurements.

show abstract

“…16 Fibrillation of WPI at low pH and high temperature has been suggested to proceed through hydrolysis of the proteins into smaller peptide fragments that spontaneously assemble into PNFs. [17][18][19] Although other whey proteins, e.g. a-lactalbumin, can also form amyloid-like brils, 20 PNFs formed under the applied conditions have been shown to be built exclusively from b-lactoglobulin-derived peptides.…”

mentioning

confidence: 99%

On the role of peptide hydrolysis for fibrillation kinetics and amyloid fibril morphology

Hedenqvist

Langton

et al. 2018

RSC Adv.

View full text Add to dashboard Cite

Self-assembly of proteins into amyloid-like nanofibrils is not only a key event in several diseases, but such fibrils are also associated with intriguing biological function and constitute promising components for new biobased materials. The bovine whey protein b-lactoglobulin has emerged as an important model protein for the development of such materials. We here report that peptide hydrolysis is the rate-determining step for fibrillation of b-lactoglobulin in whey protein isolate. We also explore the observation that blactoglobulin nanofibrils of distinct morphologies are obtained by simply changing the initial protein concentration. We find that the morphological switch is related to different nucleation mechanisms and that the two classes of nanofibrils are associated with variations of the peptide building blocks. Based on the results, we propose that the balance between protein concentration and the hydrolysis rate determines the structure of the formed nanofibrils.

show abstract

Peptides are Building Blocks of Heat-Induced Fibrillar Protein Aggregates of β-Lactoglobulin Formed at pH 2

Cited by 252 publications

References 30 publications

Flow-assisted assembly of nanostructured protein microfibers

Flow-assisted assembly of nanostructured protein microfibers

Enzyme-Induced Formation of β-Lactoglobulin Fibrils by AspN Endoproteinase

On the role of peptide hydrolysis for fibrillation kinetics and amyloid fibril morphology

Contact Info

Product

Resources

About