By means of a kinetic test, it was demonstrated
that one of the folding intermediates (Iα)
of hen lysozyme with α-domain folded and β-domain
unfolded is on the folding pathway under the classical
definition. Iα folds to the native
(N) state directly (unfolded (U) [hArr ]
Iα [hArr ] N) without having
to unfold to U and then refold to N through
alternative folding pathways as in Iα
[hArr ] U [hArr ] N.