Denaturation (biochemistry)



 

Denaturation is the major change in heat, which results in improper functioning of cell activity. Denatured proteins can exhibit a wide range of characteristics, from loss of solubility to communal aggregation. Proteins are very long strands of amino acids linked together in specific sequences.

Common examples

When food is cooked, some of its proteins become denatured. This is why boiled eggs become hard and cooked meat becomes firm.

A classic example of denaturing in proteins comes from acetone will also turn egg whites opaque and solid. The skin which forms on curdled milk is another common example of denatured protein. And the traditional Peruvian cold appetizer known as ceviche is prepared by chemically "cooking" raw fish and shellfish in an acidic citrus marinade, without heat.

Although denaturation can be irreversible, an example of reversible denaturing in proteins is the modern permanent wave technique for curling or straightening hair.

Protein denaturation

Denatured proteins can exhibit a wide range of characteristics, from loss of solubility to communal aggregation.

Background

hydrophobic elements of the protein are buried deep inside the structure and hydrophilic elements end up on the outside. The final shape of a protein determines how it interacts with its environment.

When a protein is denatured, the native state, but still functionally active.

How denaturation occurs at levels of protein structure

See also: Protein structure
  • In quaternary structure denaturation, protein sub-units are dissociated and/or the spatial arrangement of protein subunits is disrupted.
  • Tertiary structure denaturation involves the disruption of:

Loss of function

Most biological proteins lose their biological function when denatured. For example, transition states are no longer positioned to be able to do so.

Reversibility and irreversibility

In many proteins (unlike egg whites), denaturation is reversible (the proteins can regain their native state when the denaturing influence is removed). This was important historically, as it led to the notion that all the information needed for proteins to assume their native state was encoded in the primary structure of the protein, and hence in the DNA that codes for the protein.

Nucleic acid denaturation

The denaturation of hydrogen bonds between the strands are broken. This may occur during polymerase chain reaction. Nucleic acid strands realign when "normal" conditions are restored during annealing. If the conditions are restored too quickly, the nucleic acid strands may realign imperfectly.

See also
 
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