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In biochemistry, denaturation is a process in which proteins or nucleic acids lose folded structure present in their native state due to various factors, including application of some external stress or compound, such as a strong acid or base, a concentrated inorganic salt, an organic solvent (e.g., alcohol or chloroform), agitation and radiation, or heat. [3]
[31] [32] By his own account, the discovery was the serendipitous result of unintentional elevated temperature in a laboratory incubator. [33] Ritossa's observations, reported in 1962, [ 34 ] were later described as "the first known environmental stress acting directly on gene activity" [ 31 ] but were not initially widely cited.
Cellular stress response is the wide range of molecular changes that cells undergo in response to environmental stressors, including extremes of temperature, exposure to toxins, and mechanical damage. Cellular stress responses can also be caused by some viral infections. [1]
An extremozyme is an enzyme, often created by archaea, which are known prokaryotic extremophiles that can function under extreme environments. Examples of such are those in highly acidic/basic conditions, high/low temperatures, high salinity, or other factors, that would otherwise denature typical enzymes (e.g. catalase, rubisco, carbonic anhydrase). [1]
Human enzymes start to denature quickly at temperatures above 40 °C. Enzymes from thermophilic archaea found in the hot springs are stable up to 100 °C. [ 13 ] However, the idea of an "optimum" rate of an enzyme reaction is misleading, as the rate observed at any temperature is the product of two rates, the reaction rate and the denaturation ...
The malfunction of just one type of enzyme out of the thousands of types present in the human body can be fatal. An example of a fatal genetic disease due to enzyme insufficiency is Tay–Sachs disease, in which patients lack the enzyme hexosaminidase. [101] [102] One example of enzyme deficiency is the most common type of phenylketonuria.
Cyanobacterial DesA, [19] an enzyme that can introduce a second cis double bond at the delta-12 position of fatty acid bound to membrane glycerolipids. This enzyme is involved in chilling tolerance; the phase transition temperature of lipids of cellular membranes being dependent on the degree of unsaturation of fatty acids of the membrane lipids.
In human cell lines, chaperone proteins were found to compose ~10% of the gross proteome mass, [21] and are ubiquitously and highly expressed across human tissues. Chaperones are found extensively in the endoplasmic reticulum (ER), since protein synthesis often occurs in this area.