Abstract. Protein aggregation is associated with a number of human pathologies including Alzheimer's and Creutzfeldt-Jakob diseases and the systemic amyloidoses. In this study, we used the acylphosphatase from the hyperthermophilic Archaea Sulfolobus solfataricus (Sso AcP) to investigate the mechanism of aggregation under conditions in which the protein maintains a folded structure. In the presence of 15-25% (v/v) trifluoroethanol, Sso AcP was found to form aggregates able to bind specific dyes such as thioflavine T, Congo red, and 1-anilino-8-naphthalenesulfonic acid. The presence of aggregates was confirmed by circular dichroism and dynamic light scattering. Electron microscopy revealed the presence of small aggregates generally referred to as amyloid protofibrils. The monomeric form adopted by Sso AcP prior to aggregation under these conditions retained enzymatic activity; in addition, folding was remarkably faster than unfolding. These observations indicate that Sso AcP adopts a folded, although possibly distorted, conformation prior to aggregation. Most important, aggregation appeared to be 100-fold faster than unfolding under these conditions. Although aggregation of Sso AcP was faster at higher trifluoroethanol concentrations, in which the protein adopted a partially unfolded conformation, these findings suggest that the early events of amyloid fibril formation may involve an aggregation process consisting of the assembly of protein molecules in their folded state. This conclusion has a biological relevance as globular proteins normally spend most of their lifetime in folded structures.

Aggregation of the acylphosphatase from S. solfataricus. The folded and partially unfolded states can be both precursors for amyloid formation / G. PLAKOUTSI; N. TADDEI; M. STEFANI; F. CHITI. - In: THE JOURNAL OF BIOLOGICAL CHEMISTRY. - ISSN 0021-9258. - STAMPA. - 279(2004), pp. 14111-14119. [10.1074/jbc.M312961200]

Aggregation of the acylphosphatase from S. solfataricus. The folded and partially unfolded states can be both precursors for amyloid formation.

TADDEI, NICCOLO';STEFANI, MASSIMO;CHITI, FABRIZIO
2004

Abstract

Abstract. Protein aggregation is associated with a number of human pathologies including Alzheimer's and Creutzfeldt-Jakob diseases and the systemic amyloidoses. In this study, we used the acylphosphatase from the hyperthermophilic Archaea Sulfolobus solfataricus (Sso AcP) to investigate the mechanism of aggregation under conditions in which the protein maintains a folded structure. In the presence of 15-25% (v/v) trifluoroethanol, Sso AcP was found to form aggregates able to bind specific dyes such as thioflavine T, Congo red, and 1-anilino-8-naphthalenesulfonic acid. The presence of aggregates was confirmed by circular dichroism and dynamic light scattering. Electron microscopy revealed the presence of small aggregates generally referred to as amyloid protofibrils. The monomeric form adopted by Sso AcP prior to aggregation under these conditions retained enzymatic activity; in addition, folding was remarkably faster than unfolding. These observations indicate that Sso AcP adopts a folded, although possibly distorted, conformation prior to aggregation. Most important, aggregation appeared to be 100-fold faster than unfolding under these conditions. Although aggregation of Sso AcP was faster at higher trifluoroethanol concentrations, in which the protein adopted a partially unfolded conformation, these findings suggest that the early events of amyloid fibril formation may involve an aggregation process consisting of the assembly of protein molecules in their folded state. This conclusion has a biological relevance as globular proteins normally spend most of their lifetime in folded structures.
279
14111
14119
G. PLAKOUTSI; N. TADDEI; M. STEFANI; F. CHITI
File in questo prodotto:
File Dimensione Formato  
J. Biol. Chem.-2004-Plakoutsi-14111-9[1].pdf

Accesso chiuso

Tipologia: Versione finale referata (Postprint, Accepted manuscript)
Licenza: DRM non definito
Dimensione 559.79 kB
Formato Adobe PDF
559.79 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2158/308375
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 98
  • ???jsp.display-item.citation.isi??? 91
social impact