Analysis of the Folding Pathway of Chymotrypsin Inhibitor by Correlation of Φ-values with Inter-residue Contacts

The transition state for folding of chymotrypsin inhibitor 2 (CI2) is investigated by correlating Φ-values with inter-residue contacts. In agreement with former work, the strongest consolidation of secondary structure is found in the α-helix. There are correlations for tertiary structure interactions between the residues Leu49, Ile57 and the helix which have been suggested to represent the main components of the nucleation site of CI2 folding. However, correlations for tertiary structure interactions of comparable magnitude are also found in the helix-strand2-strand1-motif and between strand3and strand4.