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Amyloid fibrils from the mammalian protein prothymosin α
Author(s) -
Pavlov Nikolai A.,
Cherny Dmitry I.,
Heim Gudrun,
Jovin Thomas M.,
Subramaniam Vinod
Publication year - 2002
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(02)02572-3
Subject(s) - thioflavin , circular dichroism , fibril , chemistry , amyloid (mycology) , crystallography , biophysics , protein structure , beta sheet , electron microscope , biochemistry , biology , alzheimer's disease , optics , pathology , medicine , inorganic chemistry , physics , disease
Mammalian prothymosin α, a small (12 kDa) and extremely acidic protein (p I 3.5), is a member of the growing family of ‘natively’ unfolded proteins. We demonstrate that at low pH (∼3) and high concentrations, prothymosin α is capable of forming regular elongated fibrils with flat ribbon structure 4–5 nm in height and 12–13 nm in width as judged from scanning force and electron microscopy. These aggregates induced a characteristic spectral shift of thioflavin T fluorescence and their circular dichroism spectra were indicative of significant β‐sheet content, suggesting formation of classical amyloid. Our findings indicate that natively unfolded proteins may have a general propensity to form amyloid fibrils under conditions inducing partially folded conformations.