Specific collapse followed by slow hydrogen-bond formation of beta-sheet in the folding of single-chain monellin.

ABSTRACT: Characterization of the conformational landscapes for proteins with different secondary structures is important in elucidating the mechanism of protein folding. The folding trajectory of single-chain monellin composed of a five-stranded beta-sheet and a helix was investigated by using a pH-jump from the alkaline unfolded to native state. The kinetic changes in the secondary structures and in the overall size and shape were measured by circular dichroism spectroscopy and small-angle x-ray scattering, respectively. The formation of the tertiary structure was monitored by intrinsic and extrinsic fluorescence. A significant collapse was observed within 300 micros after the pH-jump, leading to the intermediate with a small amount of secondary and tertiary structures but with an overall oblate s

SUBMITTER: Kimura T 

PROVIDER: S-EPMC549438 | biostudies-literature | 2005 Feb

REPOSITORIES: biostudies-literature