A protein molecule can lose its specific three dimensional shape either temporarily or permanently this is referred to as Denaturation. This change in shape prevents the molecule from carrying out its normal function. These however can be caused by different agents namely:

1. Heat/Radiation
2. Heavy metals.
3. Detergents/organic solvents
4. Strong Acids.
5. Alkalis.

Although proteins denature some will again refold to their original structure, this is known as renaturation .