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Myoglobin forms amyloid fibrils by association of unfolded polypeptide segments.

ABSTRACT: Observations that beta-sheet proteins form amyloid fibrils under at least partially denaturing conditions has raised questions as to whether these fibrils assemble by docking of preformed beta-structure or by association of unfolded polypeptide segments. By using alpha-helical protein apomyoglobin, we show that the ease of fibril assembly correlates with the extent of denaturation. By contrast, monomeric beta-sheet intermediates could not be observed under the conditions of fibril formation. These data suggest that amyloid fibril formation from apomyoglobin depends on disordered polypeptide segments and conditions that are selectively unfavorable to folding. However, it is inevitable that such conditions often stabilize protein folding intermediates.

SUBMITTER: Fandrich M

PROVIDER: S-EPMC307590 | biostudies-literature | 2003 Dec

REPOSITORIES: biostudies-literature

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Myoglobin forms amyloid fibrils by association of unfolded polypeptide segments.

Fändrich Marcus M Forge Vincent V Buder Katrin K Kittler Marlis M Dobson Christopher M CM Diekmann Stephan S

Proceedings of the National Academy of Sciences of the United States of America 20031209 26

Observations that beta-sheet proteins form amyloid fibrils under at least partially denaturing conditions has raised questions as to whether these fibrils assemble by docking of preformed beta-structure or by association of unfolded polypeptide segments. By using alpha-helical protein apomyoglobin, we show that the ease of fibril assembly correlates with the extent of denaturation. By contrast, monomeric beta-sheet intermediates could not be observed under the conditions of fibril formation. The ...[more]

PMID: 14665689

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