The flip side is their ability to form harmful substances such as the nonsoluble proteins that attack cells in the brain and cause Alzheimer's and other neurological diseases. They can be made responsive to changes in acidity, mechanical forces, temperature, pressure, electrical and magnetic fields and light. They can be programmed to biodegrade. They've been called the wonder polymers of the 21st century. On one level, it seems odd that tiny mindless bits of protein can pull themselves together in very specific ways.
Some examples are schools of fish or flocks of birds.
No individual is in charge of the master plan, yet they all fall into place because they are programmed to do so. Each protein has a characteristic three-dimensional structure that has to chemically and structurally lock into place with another protein like tiny Legos. When they do this, they form extremely stable and ordered structures. Type II peptides undergo structural transformations for intermolecular and intramolecular self-assembly. Type IV peptides undergo assembly with nucleic acids to promote gene delivery.