ABSTRACT
Proteins are the biochemical tools and the structural elements of cells. Globular proteins are typically catalysts of cellular chemistry. The suggestion that globular proteins segregate hydrophobic amino acids away from the aqueous medium predated the publication of the first protein structure and was based on thermodynamic arguments. In most studies the machinery is immersed in a solvent that adds in its ovm complicated motions. There is good reason to believe that all these motions are coupled together in an intimate way. Proteins fold as they are synthesized. They can also be denatured and refolded reversibly in the laboratory. An attractive intermediate model is called the “growth-merge” mechanism. It uses the idea of nucleated secondary structure formation that proceeds with both short-range and long-range forces. The growth can occur at several places along the protein chain simultaneously. A strong feature of this model is that the growth mechanism is a largely one-dimensional process that should be fast and highly directed.
