How does protein folding get started?

This is the authors' abstract. We don't add key points for this paper.

Three models for the initiation of protein folding are considered in the light of recent experiments. The three models emphasize the possible roles of: (1) a hydrophobic collapse, (2) formation of secondary structure, or (3) formation of one or more specific interactions. Whether these models are likely to be contradictory or complementary is discussed.