What is the role of non-native intermediates of β-lactoglobulin in protein folding?

The mechanism of α→β transition in folding of β-lactoglobulin is discussed based on free energy landscape analysis of a long lattice model. It is found that helical propensity of β-lactoglobulin is driven by conformational entropy and is intrinsically coded in its native structure. We propose a view on a role of folding intermediate, which is “on-pathway” but rich in non-native structures. The present results suggest that the native structure topology plays an important role in α→β transition.