Low concentrations of sodium dodecyl sulfate induce the extension of β2-microglobulin-related amyloid fibrils at a neutral pH

Suguru Yamamoto, Kazuhiro Hasegawa, Itaru Yamaguchi, Shinobu Tsutsumi, J. Kardos, Yuji Goto, Fumitake Gejyo, Hironobu Naiki

Research output: Contribution to journalArticle

154 Citations (Scopus)

Abstract

In β2-microglobulin-related (Aβ2M) amyloidosis, partial unfolding of β2-microglobulin (β2-m) is believed to be prerequisite to its assembly into Aβ2M amyloid fibrils in vivo. Although low pH or 2,2,2-trifluoroethanol at a low concentration has been reported to induce partial unfolding of β2-m and subsequent amyloid fibril formation in vitro, factors that induce them under near physiological conditions have not been determined. Using fluorescence spectroscopy with thioflavin T, circular dichroism spectroscopy, and electron microscopy, we here show that at low concentrations, sodium dodecyl sulfate (SDS) converts natively folded β2-m monomers into partially folded, α-helix-containing conformers. Surprisingly, this results in the extension of Aβ2M amyloid fibrils at neutral pH, which could be explained basically by a first-order kinetic model. At low concentrations, SDS also stabilized the fibrils at neutral pH. These SDS effects were concentration-dependent and maximal at approximately 0.5 mM, around the critical micelle concentration of SDS (0.67 mM). As the concentration of SDS was increased above 1 mM, the α-helix content of β2-m rose to approximately 10%, while the β- sheet content decreased to approximately 20%, a change paralleled by a complete cessation of fibril extension and the destabilization of the fibrils. Detergents of other classes had no significant effect on the extension of fibrils. These findings are consistent with the hypothesis that in vivo, specific factors (e.g., phospholipids) that affect the conformation and stability of β2-m and amyloid fibrils will have significant effects on the kinetics of Aβ2M fibril formation.

Original languageEnglish
Pages (from-to)11075-11082
Number of pages8
JournalBiochemistry
Volume43
Issue number34
DOIs
Publication statusPublished - Aug 31 2004

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Amyloid
Sodium Dodecyl Sulfate
Trifluoroethanol
Circular dichroism spectroscopy
Kinetics
Critical micelle concentration
Fluorescence Spectrometry
Fluorescence spectroscopy
Micelles
Amyloidosis
Circular Dichroism
Detergents
Electron microscopy
Conformations
Phospholipids
Spectrum Analysis
Electron Microscopy
Monomers

ASJC Scopus subject areas

  • Biochemistry

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Low concentrations of sodium dodecyl sulfate induce the extension of β2-microglobulin-related amyloid fibrils at a neutral pH. / Yamamoto, Suguru; Hasegawa, Kazuhiro; Yamaguchi, Itaru; Tsutsumi, Shinobu; Kardos, J.; Goto, Yuji; Gejyo, Fumitake; Naiki, Hironobu.

In: Biochemistry, Vol. 43, No. 34, 31.08.2004, p. 11075-11082.

Research output: Contribution to journalArticle

Yamamoto, S, Hasegawa, K, Yamaguchi, I, Tsutsumi, S, Kardos, J, Goto, Y, Gejyo, F & Naiki, H 2004, 'Low concentrations of sodium dodecyl sulfate induce the extension of β2-microglobulin-related amyloid fibrils at a neutral pH', Biochemistry, vol. 43, no. 34, pp. 11075-11082. https://doi.org/10.1021/bi049262u
Yamamoto, Suguru ; Hasegawa, Kazuhiro ; Yamaguchi, Itaru ; Tsutsumi, Shinobu ; Kardos, J. ; Goto, Yuji ; Gejyo, Fumitake ; Naiki, Hironobu. / Low concentrations of sodium dodecyl sulfate induce the extension of β2-microglobulin-related amyloid fibrils at a neutral pH. In: Biochemistry. 2004 ; Vol. 43, No. 34. pp. 11075-11082.
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