Proteins are essential to life. They perform a wide variety of functions, including catalyzing chemical reactions, transporting molecules, and providing structural support. How proteins fold into their functional shapes is a fundamental question in biology.

In a new study, researchers at the University of California, Berkeley, have provided evidence for a mechanism called "nucleation-collapse." Nucleation-collapse proposes that proteins fold by first forming a small, stable nucleus of amino acids. This nucleus then grows by attracting other amino acids, causing the protein to collapse into its final shape.

The researchers tested their hypothesis using a protein called the green fluorescent protein (GFP). GFP is a small protein that glows green when exposed to blue light. The researchers engineered a version of GFP that contained a single amino acid substitution. This substitution made the protein more likely to form a stable nucleus.

The researchers found that the engineered GFP folded much faster than the wild-type GFP. This suggests that nucleation-collapse is a key mechanism of protein folding.

The findings of this study have implications for understanding how proteins misfold. Protein misfolding can lead to a variety of diseases, including Alzheimer's disease and cystic fibrosis. By understanding how proteins fold, researchers may be able to develop new drugs to prevent or treat these diseases.

The study was published in the journal Nature Structural & Molecular Biology.