ABSTRACT

Proteins can undergo cooperative changes. In a cooperative change, a small perturbation leads to a large consequence. One example was already described in Chapter 4: the binding of a ligand drives allostery or large conformational changes in a protein. Here, we consider two other examples. One is the folding process. In test tube experiments, a protein can be driven from a denatured state to its native structure sometimes by a very small change in temperature or denaturant concentration. Another example is protein aggregation, where a small increase in a protein’s concentration, under the right conditions, can drive individual proteins into large-scale multimolecular association in the form of aggregates, precipitates, crystals, or amyloid fibrils.