title: Growth of beta(2)-microglobulin-related amyloid fibrils by non-esterified fatty acids at a neutral pH.
abstract: Abeta2M (beta(2)-microglobulin-related) amyloidosis is a frequent and serious complication in patients on long-term dialysis. Partial unfolding of beta2-m (beta(2)-microglobulin) may be essential to its assembly into Abeta2M amyloid fibrils in vivo. Although SDS around the critical micelle concentration induces partial unfolding of beta2-m to an alpha-helix-containing aggregation-prone amyloidogenic conformer and subsequent amyloid fibril formation in vitro, the biological molecules with similar activity under near-physiological conditions are still unknown. The effect of various NEFAs (non-esterified fatty acids), which are representative anionic amphipathic compounds in the circulation, on the growth of Abeta2M amyloid fibrils at a neutral pH was examined using fluorescence spectroscopy with thioflavin T, CD spectroscopy, and electron microscopy. Physiologically relevant concentrations of laurate, myristate, oleate, linoleate, and mixtures of palmitate, stearate, oleate and linoleate, induced the growth of fibrils at a neutral pH by partially unfolding the compact structure of beta2-m to an aggregation-prone amyloidogenic conformer. In the presence of human serum albumin, these NEFAs also induced the growth of fibrils when their concentrations exceeded the binding capacity of albumin, indicating that the unbound NEFAs rather than albumin-bound NEFAs induce the fibril growth reaction in vitro. These results suggest the involvement of NEFAs in the development of Abeta2M amyloidosis, and in the pathogenesis of Abeta2M amyloidosis.
authors.affiliation: Division of Molecular Pathology, Department of Pathological Sciences, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji, Fukui 910-1193, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Hasegawa
authors.forename: Shinobu
authors.initials: S
authors.lastname: Tsutsumi-Yasuhara
authors.forename: Tadakazu
authors.initials: T
authors.lastname: Ookoshi
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Ohhashi
authors.forename: Hideki
authors.initials: H
authors.lastname: Kimura
authors.forename: Naoki
authors.initials: N
authors.lastname: Takahashi
authors.forename: Haruyoshi
authors.initials: H
authors.lastname: Yoshida
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Miyazaki
authors.forename: Yuji
authors.initials: Y
authors.lastname: Goto
authors.forename: Hironobu
authors.initials: H
authors.lastname: Naiki
mesh_terms: D000682:Amyloid / Q000187:drug effects / Q000378:metabolism*; D000686:Amyloidosis / Q000209:etiology; D005230:Fatty Acids, Nonesterified / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008823:Micelles; D010084:Oxidation-Reduction; D010712:Phosphatidic Acids / Q000494:pharmacology; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D006435:Renal Dialysis / Q000009:adverse effects; D001613:beta 2-Microglobulin / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*
chemical_list: D000682:Amyloid; D005230:Fatty Acids, Nonesterified; D008823:Micelles; D010712:Phosphatidic Acids; D011994:Recombinant Proteins; D001613:beta 2-Microglobulin