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Macromolecular crowding converts the human recombinant PrP c to the soluble neurotoxic β‐oligomers
Author(s) -
Huang Liqin,
Jin Rui,
Li Jiarui,
Luo Kan,
Huang Tao,
Wu Di,
Wang Wenxi,
Chen Rui,
Xiao Gengfu
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.09-150987
Subject(s) - recombinant dna , thioflavin , circular dichroism , oligomer , chemistry , gene isoform , macromolecular crowding , macromolecule , intracellular , biochemistry , prion protein , biophysics , protein folding , microbiology and biotechnology , biology , medicine , disease , organic chemistry , pathology , alzheimer's disease , gene
Prion diseases are fatal neurodegenerative disorders and are linked with the conversion of the cellular isoform of the prion protein (PrP c ) into the abnormal β‐sheet‐rich isoform. It is widely accepted that the soluble oligomers of β‐PrP are neurotoxic and that they are more pathologically significant. To unravel the molecular mechanism under the conversion process, it is critical to identify the factors that can promote the conversion from PrP c to the β‐oligomers. By recording circular dichroism spectra and performing a size‐exclusion HPLC assay, we found that the conformation of the recombinant human prion protein (rPrP c ) was converted from an α‐helical conformation into β‐sheet oligomers under a macromolecular crowding condition. The soluble β‐oligomers of rPrP were resistant to proteinase K digestion and could bind to the dyes thioflavin T and 8‐anilino‐1‐naphthalene sulfonate. Furthermore, by the 3‐(4, 5‐dimethylthiazol‐2‐yl)‐5‐(3‐carboxymethoxyphenyl)‐2‐(4‐sulfophenyl)‐2 H ‐tetrazolium assay, we showed that the soluble β‐oligomers were neurotoxic. These results suggest that macromolecular crowding, which has not been considered before, is a key intracellular factor in the formation of soluble neurotoxic β‐oligomers in prion diseases.—Huang, L., Jin, R., Li, J., Luo, K., Huang, T., Wu, D., Wang, W., Chen, R., Xiao, G. Macromolecular crowding converts the human recombinant PrP c to the soluble neurotoxic β‐oligomers. FASEB J . 24, 3536–3543 (2010). www.fasebj.org