Amyloid-β-protein (Aβ) (25-35)-associated free radical generation is strongly influenced by the aggregational state of the peptides

Akira Monji, Hideo Utsumi, Tadashi Ueda, Taiji Imoto, Ichiro Yoshida, Sadayuki Hashioka, Ken Ichiro Tashiro, Nobutada Tashiro

Research output: Contribution to journalArticlepeer-review

30 Citations (Scopus)

Abstract

We investigated whether or not the Amyloid-β-protein (Aβ) itself spontaneously generates free radicals using electron spin resonance (ESR) spectroscopy while also monitoring the aggregational state of Aβ and Aβ-induced cytotoxicity. The present results demonstrated a four-line spectrum in the presence of Aβ25-35 with N-tert-butyl-α-phenylnitrone (PBN) but not in the presence of PBN alone in phosphate-buffered saline (PBS). The fact that the four-line spectrum obtained for the Aβ25-35/PBN in PBS was completely abolished in the presence of the iron-chelating agent Desferal demonstrated the observed four-line spectrum to be iron-dependent. On the other hand, Aβ25-35 with PBN in phosphate buffer (PB) did not produce any definite four-line spectrum. The present results showed the amyloid fibril formation of Aβ25-35 in PBS to be much higher than that of Aβ25-35 in PB. Moreover, Aβ-induced cytotoxicity assays showed Aβ incubated in PBS to be more cytotoxic than that incubated in PB. These results thus demonstrate that Aβ(25-35) - associated free radical generation is strongly influenced by the aggregational state of the peptides.

Original languageEnglish
Pages (from-to)833-841
Number of pages9
JournalLife Sciences
Volume70
Issue number7
DOIs
Publication statusPublished - Jan 4 2002

All Science Journal Classification (ASJC) codes

  • Biochemistry, Genetics and Molecular Biology(all)
  • Pharmacology, Toxicology and Pharmaceutics(all)

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