The content of oxidized proteins is widely used to estimate the intensity of stress in vivo. The most commonly used method is the determination of the protein content of one of the stable products - carbonyl groups additionally formed. In the following states of the organism activation of free radical processes is reliably established.
Aging
In the course of aging, oxidized proteins accumulate, and since additional carboxylic groups are formed during the oxidation of any form of ROS, they are used as markers.
Professor R. Sohal studied the relationship between the accumulation of carbonyl groups and the life expectancy of organisms. He revealed a pattern that moderate hyperoxia, which increases the concentration of protein carbonyls, reduces life expectancy. And since the increase in the formation of ROS in MTX of aging organisms is closely related to the accumulation of protein carbonyls, it is the oxidation of proteins that is responsible for the aging process.
Thus, the introduction of a spin trap with antioxidant properties (BFN) to sand larvae and indoor flies reduced the level of protein carbonyls, which led to an increase in life expectancy. A change in cognitive and motor functions in mice is associated with the accumulation of protein carbonyls depending on age. The increase of protein carbonyls led to the decrease of learning ability, and the increase of protein oxidation in the cerebellum led to the loss of motor concentration.
If this theory of aging is correct, and most scientists are inclined to do so, it is possible to slow down aging by reducing the intensity of ROS generation or increasing the rate of its degradation. It is possible to do this by using antioxidants or by reducing the caloric value of food without disturbing balanced nutrition.
The graph shows the dependence of carbonyl groups in different tissues of different organisms on the age of the individual. With its increase the content of carbonyl groups in the body increases. This graph proves this theory.
Ischemia-reperfusion
In ischemia, oxygen levels in the tissues are below normal. At the same time, the intensity of the generation of ROS, carbonyl groups decreases, and the recovery of the intracellular environment increases.
At 10-minute ischemia of sand lupus caused by the overlap of two carotid arteries, the level of protein carbonyls increased quite rapidly during reperfusion. At the same time, a link was established between the content of protein carbonyls and the activity of glathaminsinthetase (HS) - the more protein carbonyls, the less HS activity. A decrease in the activity of this enzyme leads to an increase in the content of glutamate, which may be a critical factor leading to neurotoxicity and brain damage in ischemia-reperfusion.
Neurodegenerative diseases (Alzheimer's, Parkinson's, sclerosis).
Let's take Parkinson's disease as an example. This disorder is characterized by an increase in iron content in substancia nigra pars compacta. The root cause of this disorder is oxidative stress accompanied by the intensification of lipid peroxide oxidation. Development occurs under the influence of β-amyloid. Amyloid peptides are combined into structures that begin to show neurotoxicity, disturb the homeostasis of calcium ions and accumulate iron ions. This chain aggravates the state of the body and leads to even greater development of the disease.
In patients suffering from Alzheimer's disease, the content of protein carbonyls does not differ from the control, but the activity of HS is below normal. As mentioned above, the decrease in the activity of this enzyme leads to an increase in glutamate content, which can be a critical factor leading to neurotoxicity and brain damage.
Diabetes
The reason is mainly the lack of insulin formation by β-cells of the pancreas, which is mainly preceded by the development of oxidative stress in the cells. An important point is antioxidative glycosylation.
Atherosclerosis
It has been established that the oxidation of macromolecules is closely related to the development of atherosclerosis. Most of the accumulated lipids are formed from low-density lipoproteins. Modification of their protein apo form by aldehydes and oxidation of lipids is considered a key factor in the formation of plaques in atherosclerosis. The high content of 3-nitrotyrosine in plaque proteins.