Phi-values for BPTI folding intermediates and implications for transition state analysis.

G Bulaj; D P Goldenberg

doi:10.1038/86200

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Phi-values for BPTI folding intermediates and implications for transition state analysis.

G Bulaj·D P Goldenberg

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Abstract

Amino acid replacements were used to probe the roles of 14 sites in two well-characterized intermediates in the folding pathway of bovine pancreatic trypsin inhibitor (BPTI). One of these intermediates contains one of the three disulfides found in the native protein (30--51). NMR studies have shown that approximately two-thirds of this polypeptide has a native-like conformation. The other intermediate contains two native disulfides (30--51 and 5--55) and has a fully folded conformation. The phi-values for a majority of residues were <1, indicating that the native protein was significantly more destabilized than either intermediate even when the altered residue was located in a well-ordered region of the intermediate. These observations suggest that folding intermediates and transition states may generally be more structured than indicated by phi-values alone.

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Amino Acid Substitution Animals Aprotinin Cattle Disulfides Kinetics Models, Molecular Mutation Protein Conformation Protein Denaturation Protein Folding Thermodynamics Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S.

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G Bulaj, D P Goldenberg. 2001. Phi-values for BPTI folding intermediates and implications for transition state analysis.. https://doi.org/10.1038/86200

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