Related Experiment Video
Updated: Jun 17, 2026
09:43
Purification and Refolding to Amyloid Fibrils of (His)6-tagged Recombinant Shadoo Protein Expressed as Inclusion Bodies in E. coli
Published on: December 19, 2015
Wild-type Shadoo proteins convert to amyloid-like forms under native conditions
Nathalie Daude1, Vivian Ng, Joel C Watts
1Centre for Prions and Protein Folding Diseases, University of Alberta, Alberta, Canada.
Journal of Neurochemistry
|January 14, 2010
Summary
Shadoo (Sho), a brain glycoprotein, can form amyloid structures similar to prion protein (PrP). These findings reveal a proteinase K-resistant core, suggesting a potential physiological role for this amyloid form.
Area of Science:
- Neuroscience
- Biochemistry
- Structural Biology
Background:
- The cellular prion protein (PrP(C)) refolds into a beta-sheet enriched, infectivity-associated form (PrP(Sc)).
- Shadoo (Sho) is a newly discovered glycoprotein expressed in the adult brain, sharing structural similarities with PrP(C).
Purpose of the Study:
- To investigate the conformational properties of wild-type (wt) mouse Sho and its polymorphic variants.
- To determine if Sho can form amyloid-like structures and characterize their properties.
Main Methods:
- Recombinant mouse and sheep Sho were used to study amyloid formation.
- Conformational changes were assessed using thioflavin T binding, Congo red staining, electron microscopy, and sodium dodecyl sulfate-resistance assays.
- Proteinase K digestion was employed to identify resistant fragments.
Main Results:
- Recombinant Sho converted to an amyloid-like form without chemical denaturation.
- This transition was characterized by increased thioflavin T binding, Congo red staining, fibrillar structures, and SDS-resistant complexes.
- A proteinase K-resistant core fragment (5-8 kDa) was generated for wt Sho, indicating an amyloid fold.
Conclusions:
- Wild-type Sho can adopt an amyloid-like conformation with distinct biochemical and structural properties.
- Polymorphic variants showed similar but not identical amyloidogenic properties.
- The study defines a proteinase K-resistant signature for Sho amyloid and suggests a potential physiological role for this conformation.
Related Concept Videos
03:03Amyloid Fibrils
Amyloid fibrils are aggregates of misfolded proteins. Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils.
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
03:03Amyloid Fibrils
Amyloid fibrils are aggregates of misfolded proteins. Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils.
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
01:25Protein Folding
Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence.
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
01:23Alzheimer Disease ll: Pathophysiology
Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and microglia. Abnormal...
02:15Protein and Protein Structure
Proteins are one of the most abundant organic molecules in living systems and have the most diverse range of functions of all macromolecules. Proteins may be structural, regulatory, contractile, or protective. They may serve in transport, storage, or membranes; or they may be toxins or enzymes. Their structures, like their functions, vary greatly. They are all, however, amino acid polymers arranged in a linear sequence.
A protein's shape is critical to its function. For example, an enzyme can...
A protein's shape is critical to its function. For example, an enzyme can...
01:39Mutations
Overview