Staphylococcal protein A: unfolding pathways, unfolded states, and differences between the B and E domains.

ABSTRACT: We present multiple native and denaturation simulations of the B and E domains of the three-helix bundle protein A, totaling 60 ns. The C-terminal helix (H3) consistently denatures later than either of the other two helices and contains residual helical structure in the denatured state. These results are consistent with experiments suggesting that the isolated H3 fragment is more stable than H1 and H2 and that H3 forms early in folding. Interestingly, the denatured state of the B domain is much more compact than that of the E domain. This sequence-dependent effect on the dimensions of the denatured state and the lack of correlation with structure suggest that the radius of gyration can be a misleading reaction coordinate for unfolding/folding. Various unfolding and refolding events are obs

SUBMITTER: Alonso DO 

PROVIDER: S-EPMC26628 | biostudies-literature | 2000 Jan

REPOSITORIES: biostudies-literature