Discriminating Strains of Self-Propagating Protein Aggregates Using a Conformational Stability Assay
Prions and other self-propagating protein aggregates can exist as distinct strains, which are thought to represent different conformations of aggregates. There is growing evidence that protein aggregate strains may be important for understanding the biology of common neurodegenerative disorders, such as Alzheimer’s disease and Parkinson’s disease. While methodology for discriminating prion strains is in widespread use, there is a paucity of tools for comparing the conformational properties of aggregates composed of β-amyloid (Aβ) peptide or α-synuclein protein, particularly when present in complex samples such as brain extracts. The conformational stability assay (CSA) is a simple technique that measures the relative resistance of protein aggregates to chemical denaturation. While originally developed to differentiate prion strains, the CSA has since been adapted for use with other protein aggregates. Here, we describe the CSA in detail and outline its utility for distinguishing prion strains as well as unique conformational states of Aβ and α-synuclein aggregates.
Key wordsProtein aggregates Protein misfolding Strains Prions Amyloid α-Synuclein Alzheimer’s disease Parkinson’s disease Creutzfeldt-Jakob disease Self-propagation
- 17.Cohen ML, Kim C, Haldiman T, ElHag M, Mehndiratta P, Pichet T, Lissemore F, Shea M, Cohen Y, Chen W, Blevins J, Appleby BS, Surewicz K, Surewicz WK, Sajatovic M, Tatsuoka C, Zhang S, Mayo P, Butkiewicz M, Haines JL, Lerner AJ, Safar JG (2015) Rapidly progressive Alzheimer’s disease features distinct structures of amyloid-beta. Brain 138(Pt 4):1009–1022CrossRefPubMedGoogle Scholar
- 22.Prusiner SB, Woerman AL, Mordes DA, Watts JC, Rampersaud R, Berry DB, Patel S, Oehler A, Lowe JK, Kravitz SN, Geschwind DH, Glidden DV, Halliday GM, Middleton LT, Gentleman SM, Grinberg LT, Giles K (2015) Evidence for alpha-synuclein prions causing multiple system atrophy in humans with parkinsonism. Proc Natl Acad Sci U S A 112(38):E5308–E5317CrossRefPubMedGoogle Scholar
- 27.Angers RC, Kang HE, Napier D, Browning S, Seward T, Mathiason C, Balachandran A, McKenzie D, Castilla J, Soto C, Jewell J, Graham C, Hoover EA, Telling GC (2010) Prion strain mutation determined by prion protein conformational compatibility and primary structure. Science 328:1154–1158CrossRefPubMedGoogle Scholar
- 28.Safar JG, Scott M, Monaghan J, Deering C, Didorenko S, Vergara J, Ball H, Legname G, Leclerc E, Solforosi L, Serban H, Groth D, Burton DR, Prusiner SB, Williamson RA (2002) Measuring prions causing bovine spongiform encephalopathy or chronic wasting disease by immunoassays and transgenic mice. Nat Biotechnol 20:1147–1150CrossRefGoogle Scholar