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Polymorphism of amyloid-like fibrils can be defined by the concentration of seeds.

Sneideris T, Milto K, Smirnovas V - PeerJ (2015)

Bottom Line: The strains are enciphered by different misfolded conformations.Strain-like phenomena have also been reported in a number of other amyloid-forming proteins.Our findings could explain conformational switching between amyloid strains observed in a wide variety of in vivo and in vitro experiments.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biothermodynamics and Drug Design, Vilnius University, Institute of Biotechnology , Vilnius , Lithuania.

ABSTRACT
Prions are infectious proteins where the same protein may express distinct strains. The strains are enciphered by different misfolded conformations. Strain-like phenomena have also been reported in a number of other amyloid-forming proteins. One of the features of amyloid strains is the ability to self-propagate, maintaining a constant set of physical properties despite being propagated under conditions different from those that allowed initial formation of the strain. Here we report a cross-seeding experiment using strains formed under different conditions. Using high concentrations of seeds results in rapid elongation and new fibrils preserve the properties of the seeding fibrils. At low seed concentrations, secondary nucleation plays the major role and new fibrils gain properties predicted by the environment rather than the structure of the seeds. Our findings could explain conformational switching between amyloid strains observed in a wide variety of in vivo and in vitro experiments.

No MeSH data available.


Related in: MedlinePlus

AFM images of rMoPrP amyloid-like aggregates.(A) and (B) show fibrils of rPrP-A4M and rPrP-A2M strains, (C) and (D) show fibrils formed during cross-seeding in the presence of 5% and 0.2% seeds, respectively.
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fig-3: AFM images of rMoPrP amyloid-like aggregates.(A) and (B) show fibrils of rPrP-A4M and rPrP-A2M strains, (C) and (D) show fibrils formed during cross-seeding in the presence of 5% and 0.2% seeds, respectively.

Mentions: AFM analysis did not reveal any major differences between rPrP-A4M and rPrP-A2M strains (Figs. 3A and 3B). In both cases fibril diameters range from 4 to 16 nm, however thicker fibrils are more often in samples of rPrP-A2M strains. This difference is more obvious when comparing fibrils formed in presence of 5% and 0.2% seeds (Figs. 3C and 3D). The majority of fibrils formed in presence of high amount of seeds are 4–8 nm in diameter, while these formed at low seed concentration are usually 8–16 nm.


Polymorphism of amyloid-like fibrils can be defined by the concentration of seeds.

Sneideris T, Milto K, Smirnovas V - PeerJ (2015)

AFM images of rMoPrP amyloid-like aggregates.(A) and (B) show fibrils of rPrP-A4M and rPrP-A2M strains, (C) and (D) show fibrils formed during cross-seeding in the presence of 5% and 0.2% seeds, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4563235&req=5

fig-3: AFM images of rMoPrP amyloid-like aggregates.(A) and (B) show fibrils of rPrP-A4M and rPrP-A2M strains, (C) and (D) show fibrils formed during cross-seeding in the presence of 5% and 0.2% seeds, respectively.
Mentions: AFM analysis did not reveal any major differences between rPrP-A4M and rPrP-A2M strains (Figs. 3A and 3B). In both cases fibril diameters range from 4 to 16 nm, however thicker fibrils are more often in samples of rPrP-A2M strains. This difference is more obvious when comparing fibrils formed in presence of 5% and 0.2% seeds (Figs. 3C and 3D). The majority of fibrils formed in presence of high amount of seeds are 4–8 nm in diameter, while these formed at low seed concentration are usually 8–16 nm.

Bottom Line: The strains are enciphered by different misfolded conformations.Strain-like phenomena have also been reported in a number of other amyloid-forming proteins.Our findings could explain conformational switching between amyloid strains observed in a wide variety of in vivo and in vitro experiments.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biothermodynamics and Drug Design, Vilnius University, Institute of Biotechnology , Vilnius , Lithuania.

ABSTRACT
Prions are infectious proteins where the same protein may express distinct strains. The strains are enciphered by different misfolded conformations. Strain-like phenomena have also been reported in a number of other amyloid-forming proteins. One of the features of amyloid strains is the ability to self-propagate, maintaining a constant set of physical properties despite being propagated under conditions different from those that allowed initial formation of the strain. Here we report a cross-seeding experiment using strains formed under different conditions. Using high concentrations of seeds results in rapid elongation and new fibrils preserve the properties of the seeding fibrils. At low seed concentrations, secondary nucleation plays the major role and new fibrils gain properties predicted by the environment rather than the structure of the seeds. Our findings could explain conformational switching between amyloid strains observed in a wide variety of in vivo and in vitro experiments.

No MeSH data available.


Related in: MedlinePlus