Protein denaturation is a process where proteins lose high levels of structure, including secondary, tertiary, and quaternary structures, by application of some external stress or compounds. Examples of external stimulation for denaturation are strong acid or base, concentrated inorganic salt, organic solvent, radiation, and heat. Denatured proteins lose their 3D structure, which may result in a variety of consequences such as loss of solubility, aggregation due to the exposure of hydrophobic group, and ultimately loss of function.