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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

FTIR spectra of rPrP amyloid-like fibrils.
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fig-4: FTIR spectra of rPrP amyloid-like fibrils.

Mentions: FTIR spectra of rMoPrP amyloid-like fibrils display major band in the amide I/I’ region, corresponding to beta-sheet structure with subtle difference in band frequencies between rPrP-A4M and rPrP-A2M strains (Fig. 4). The spectrum of rPrP-A4M strain is very similar to the spectrum of fibrils, prepared in the presence of 5% seeds; both show peak maxima at ∼1,620 cm−1. The spectrum of rPrP-A2M strain and the spectrum of fibrils, prepared in the presence of 0.2% seeds show peak maxima at ∼1,624 cm−1. This data serve as additional confirmation that propagation of the strain-specific structure depends on the amount of seeds and possibly on the mechanism of aggregation.


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

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

FTIR spectra of rPrP amyloid-like fibrils.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig-4: FTIR spectra of rPrP amyloid-like fibrils.
Mentions: FTIR spectra of rMoPrP amyloid-like fibrils display major band in the amide I/I’ region, corresponding to beta-sheet structure with subtle difference in band frequencies between rPrP-A4M and rPrP-A2M strains (Fig. 4). The spectrum of rPrP-A4M strain is very similar to the spectrum of fibrils, prepared in the presence of 5% seeds; both show peak maxima at ∼1,620 cm−1. The spectrum of rPrP-A2M strain and the spectrum of fibrils, prepared in the presence of 0.2% seeds show peak maxima at ∼1,624 cm−1. This data serve as additional confirmation that propagation of the strain-specific structure depends on the amount of seeds and possibly on the mechanism of aggregation.

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