Selenomethionine incorporation into amyloid sequences regulates fibrillogenesis and toxicity.

Autor: Javier Martínez, Silvia Lisa, Rosa Sánchez, Wioleta Kowalczyk, Esther Zurita, Meritxell Teixidó, Ernest Giralt, David Andreu, Jesús Avila, María Gasset
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Zdroj: PLoS ONE, Vol 6, Iss 11, p e27999 (2011)
Druh dokumentu: article
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0027999
Popis: BACKGROUND: The capacity of a polypeptide chain to engage in an amyloid formation process and cause a conformational disease is contained in its sequence. Some of the sequences undergoing fibrillation contain critical methionine (Met) residues which in vivo can be synthetically substituted by selenomethionine (SeM) and alter their properties. METHODOLOGY/PRINCIPAL FINDINGS: Using peptide synthesis, biophysical techniques and cell viability determinations we have studied the effect of the substitution of methionine (Met) by selenomethionine (SeM) on the fibrillogenesis and toxic properties of Aβ40 and HuPrP(106-140). We have found that the effects display site-specificity and vary from inhibition of fibrillation and decreased toxicity ([SeM(35)]Aβ40, [SeM(129)]HuPrP(106-140) and [SeM(134)]HuPrP(106-140)), retarded assembly, modulation of polymer shape and retention of toxicity ([SeM(112)]HuPrP(106-140) to absence of effects ([SeM(109)]HuPrP(106-140)). CONCLUSIONS/SIGNIFICANCE: This work provides direct evidence that the substitution of Met by SeM in proamyloid sequences has a major impact on their self-assembly and toxic properties, suggesting that the SeM pool can play a major role in dictating the allowance and efficiency of a polypeptide chain to undergo toxic polymerization.
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