Unfolding of tertiary structures of proteins.
Wakana, H., Yokomizo, H., Wako, H., Isogai, Y., Kosuge, K. & Saito, N.
Int. J. Pept. Protein Res. (1984) 23, 657-670.
Abstract
The unfolding pathway of lysozyme was investigated by carrying out
the computer simulation. Taking into account the simultaneous change of
both the dihedral angels phi and psi of a residue, we explore the detailed
features of the conformational energy profiles. The triangle distance map
shows that the lysozyme molecule is divided into three domains, 1-40, 41-101
and 102-129 in amino acid residue numbers (referred to as the domains I,
II and III, respectively). The calculated unfolding process indicates that
in the early stage of unfolding domain III located at the C-terminal begins
to be detached from the other two, and then domain I can be unfolded. The
long-range interactions between domains I and III stabilize the whole molecule
and give the cooperative nature of the folding. The calculated unfolding
pathway of lysozyme is consistent with the folding pathway proposed by
Anderson & Wetlaufer [J. Biol. Chem. (1976). 251, 3147-3153] who identified
the disulfide bondings in the early stage of the glutathione regeneration.
A simplified treatment of unfolding for myoglobin is also discussed in
the Appendix.