Initiation sites of protein folding by NMR analysis.

AUTOR(ES)

Freund, S M

RESUMO

Detailed characterization of denatured states of proteins is necessary to understand the interactions that funnel the large number of possible conformations along fast routes for folding. Nuclear magnetic resonance experiments based on the nuclear Overhauser effect (NOE) detect hydrogen atoms close in space and provide information about local structure. Here we present an NMR procedure that detects almost all sequential NOEs between amide hydrogen atoms (HN-HN NOE), including those in random coil regions in a protein, barnase, in urea solutions. A semi-quantitative analysis of these HN-HN NOEs identified partly structured regions that are in remarkable agreement with those found to form early on the reaction pathway. Our results strongly suggest that the folding of barnase initiates at the first helix and the beta-turn between the third and the fourth strands. This strategy of defining residual structure has also worked for cold-denatured barstar and guanidinium hydrochloride-denatured chymotrypsin inhibitor 2 and so should be generally applicable.

Documentos Relacionados

• Mapping of replication initiation sites in human ribosomal DNA by nascent-strand abundance analysis.
• Dynamic NMR spectral analysis and protein folding: identification of a highly populated folding intermediate of rat intestinal fatty acid-binding protein by 19F NMR.
• Native-like in vivo folding of a circularly permuted jellyroll protein shown by crystal structure analysis.
• Contacting the protein folding funnel with NMR
• Mapping of replication initiation site in Mycoplasma capricolum genome by two-dimensional gel-electrophoretic analysis.