To denature a
protein means to alter or disrupt its natural three-dimensional structure without breaking the peptide bonds that form its primary amino-acid sequence. Denaturation can be caused by heat, acids, bases, salts, mechanical action, or other conditions.
When a protein denatures, its secondary, tertiary, and/or quaternary structures may change or unfold. This can affect properties such as solubility, texture, water-holding capacity, and functionality.
Example: When an egg is heated, the proteins in the egg white denature and unfold, then interact with one another to form a more solid network. This changes the egg white from a clear, fluid substance into an opaque, firm one.
Denaturation does not necessarily mean that the protein is completely destroyed. Its amino-acid sequence (primary structure) generally remains intact.