Abstract
BetaCore is a designed ∼50-residue protein in which two BPTI-derived core modules, CM I and CM II, are connected by a 22-atom cross-link. At low temperature and pH 3, homo- and heteronuclear NMR data report a dominant folded ('f') conformation with well-dispersed chemical shifts, i, i+1 periodicity, numerous long-range NOEs, and slowed amide hydrogen isotope exchange patterns that is a four-stranded antiparallel β-sheet with nonsymmetrical and specific association of CM I and CM II. BetaCore 'f' conformations undergo reversible, global, moderately cooperative, non-two-state thermal transitions to an equilibrium ensemble of unfolded 'u' conformations. There is a significant energy barrier between 'f' and 'u' conformations. This is the first designed four-stranded antiparallel β-sheet that folds in water.
Original language | English (US) |
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Pages (from-to) | 1539-1551 |
Number of pages | 13 |
Journal | Protein Science |
Volume | 11 |
Issue number | 6 |
DOIs | |
State | Published - 2002 |
Keywords
- Core modules
- Cross-link
- Protein design
- Protein folding
- β-sheet protein