denaturate

Denaturate is the verb form of denature, referring to the process of altering the natural structure or properties of a substance so that it no longer behaves as it normally would. In biology and chemistry, denaturation most commonly refers to proteins and nucleic acids and to liquids used for industrial or laboratory purposes.

In proteins, denaturation involves disruption of the native three-dimensional conformation (secondary, tertiary, and quaternary structures) caused by heat, changes in pH, salts, organic solvents, or detergents. Noncovalent interactions such as hydrogen bonds, hydrophobic effects, and ionic bonds are broken or weakened. Denaturation typically results in loss of enzymatic activity or binding capability. Some proteins can renature if the environment is restored and if disulfide bonds and aggregation have not occurred; for many proteins, denaturation is irreversible.

In nucleic acids, denaturation refers to separation of double-stranded DNA or RNA into single strands, usually by heat or chemical agents. The term melting temperature describes the point where half of the double helix is denatured; GC content and ionic strength influence this temperature.

In industrial contexts, denaturation also describes rendering a substance unusable as a consumable product, such as denatured alcohol, which contains additives to discourage drinking. This is done to prevent beverage use or to designate products for industrial use or fuel.

Common laboratory denaturants include heat, acids or bases, urea, guanidinium chloride, and surfactants such as SDS; organic solvents like ethanol or methanol can also denature proteins or nucleic acids.

Note that denaturation is distinct from chemical bond cleavage; often it preserves the primary sequence while altering higher-order structure, though it can lead to irreversible damage in some cases.