molecular biology Molecular biology is a branch of biology that seeks to understand the molecule, molecular basis of biological activity in and between Cell (biology), cells, including biomolecule, biomolecular synthesis, modification, mechanisms, and interactio ...

, an Anfinsen cage is a model for

protein folding Protein folding is the physical process by which a protein, after Protein biosynthesis, synthesis by a ribosome as a linear chain of Amino acid, amino acids, changes from an unstable random coil into a more ordered protein tertiary structure, t ...

used by some cells to improve the production speed and yield of accurate products. Space within a cell is generally limited, and a protein's folding process can be interrupted or modified if it wanders too close to outside forces while it is still in the process of forming. Even worse, the unformed molecules may begin to aggregate uncontrollably, potentially resulting in a disease such as

Alzheimer's Alzheimer's disease (AD) is a neurodegenerative disease and the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As the disease advances, symptoms can include problems wit ...

. To prevent this, some cells will enclose actively folding proteins within one or more chaperones, forming a "cage" around them to protect them during their transformation. These cages can also serve to isolate incorrectly formed proteins that may otherwise affect other processes if it were allowed to float freely. The model is named after Christian B. Anfinsen who first showed

in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

that pure denatured proteins will sometimes refold spontaneously without an energy source.

References

Protein folding {{molecular-biology-stub