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Updated: Jul 4, 2026
05:48
Rapid Generation of Amyloid from Native Proteins In vitro
Published on: December 5, 2013
Beta-lactoglobulin assembles into amyloid through sequential aggregated intermediates
Jason T Giurleo1, Xianglan He, David S Talaga
1Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 610 Taylor Road, Piscataway, NJ 08854, USA.
Journal of Molecular Biology
|July 2, 2008
Summary
Bovine beta-lactoglobulin aggregation involves three stages: initial weak aggregation, formation of stable globular aggregates, and finally, conversion into amyloid protofibrils. This process involves conformational changes and disruption of the protein's calyx.
Area of Science:
- Biochemistry
- Protein aggregation
- Amyloid formation
Background:
- Bovine beta-lactoglobulin (BB-LG) is a major whey protein.
- Protein aggregation can lead to amyloid fibril formation, associated with various diseases.
- Understanding early aggregation stages is crucial for controlling protein behavior.
Purpose of the Study:
- To investigate the early aggregation stages and amyloid fibril formation of bovine beta-lactoglobulin variant A.
- To elucidate the conformational changes during aggregation using spectroscopic probes.
- To correlate aggregation kinetics and morphology with protein structural alterations.
Main Methods:
- Noncovalent labeling with Thioflavin T (amyloid formation) and 1-anilino-8-naphthalenesulfonate (hydrophobic core changes).
- Time-resolved luminescence spectroscopy to monitor conformational dynamics.
- Dynamic light scattering and atomic force microscopy to assess aggregate size and morphology.
- Aggregation reversibility assays to evaluate intermediate stability.
Main Results:
- Initial aggregation (0-5 days) showed partial disruption of the BB-LG calyx.
- Globular aggregate formation (5-16 days) led to complete calyx disruption and increased stability.
- Subsequent conversion to fibrillar forms (growth phase) was accompanied by further luminescence changes.
- A three-step aggregation pathway was proposed: monomer to weak aggregates, to stable aggregates, to protofibrils.
Conclusions:
- The aggregation of BB-LG is a multi-step process involving significant conformational changes.
- Early aggregation stages are characterized by the disruption of the protein's hydrophobic core.
- The study provides a detailed mechanistic insight into BB-LG amyloid fibril formation.
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