Views: 0 Author: Site Editor Publish Time: 2023-03-17 Origin: Site
Carnosine is a water-soluble dipeptide that occurs naturally in the skeletal muscle of many vertebrates and in the metabolically active brain. It was first discovered in 1900 by the Russian scholar Gulewitsch. He isolated myostatin from Liebig's meat extract, which was later shown to have the structure of β-alanyl-L-histidine. The structure of myostatin is shown in the figure. This was the first representative bioactive peptide isolated from a natural raw material.
Since Gulewitsch first isolated myostatin more than 100 years ago, scholars from different countries have isolated histidine dipeptides from different muscle tissues, such as goose myostatin (β-alanyl-1-methyl L-histidine, Anserine), whale myostatin (β-alanyl-3-methyl L-histidine, Balenine, also known as Ophidine,), N-acetyl-carnitine and other dipeptides. The content of myostatin varies from animal to animal. Japanese scholar Mano et al. compared the content of myostatin in some fish and shellfish, and found that myostatin was abundant in eel and bonito, and high in moray eel and cuttlefish, but little in mackerel, sardine, flounder and sea carp. The content of myostatin in different muscle tissues of the same species is also different, for example, the content of myostatin in the back muscle of tuna is higher than that in the abdominal muscle, the concentration of myostatin in the leg meat of pig is higher than that in the scapula, and the concentration of myostatin in the white muscle is higher than that in the red muscle.
Moreover, the content of histidine dipeptide and the ratio of the content of various dipeptides are different among different species and have some specificity. Since histidine dipeptide is not greatly affected by cooking and other processes, the content of histidine dipeptide and the ratio between various dipeptides can be measured to indirectly identify the raw materials used in some meat products. The ratio of histidine dipeptides to other dipeptides can be used to indirectly identify the ingredients used in some meat products. The Ans/Car ratio has been used to identify the content of chicken in luncheon meat and the content of serpentine peptide in canned ham and sausage to identify the content of lean meat.
Moreover, in addition to the presence of histidine dipeptides in muscle tissue, these dipeptides are also present in other tissues. Biochemical analysis revealed the presence of dipeptides such as myostatin in the nervous system of lower vertebrates. Immunocytochemical studies have shown that in the brains of reptiles and amphibians, dipeptides related to myostatin are present in neuroglia, whereas in the brains of caecilians, they are present only in neuronal cells. In reptiles, these dipeptides are also present in olfactory receptor neurons. In mammals, myostatin is present in high levels in the olfactory bulb and in relatively low levels in the brain and spinal cord.
1. Physiological pH buffering
Bate Smith was the first to suggest that myostatin had a physiological pH buffering function, which was the first biological function discovered for myostatin. In 1938, Bate Smith first reported a pK value of 6.9 for myostatin and 7.1 for goose myostatin. This suggests that these two compounds are ideal physiological pH buffers. This pH buffering ability is of great importance for fish and whales that are strong swimmers. During intense anaerobic exercise such as predation or evasion, the muscle pH decreases due to the further hydrolysis of ATP generated during glycolysis reactions to produce hydrogen ions. The histidine dipeptide maintains the acid-base balance within the muscle and keeps the anaerobic locomotor capacity at a certain level. The main buffering capacity in white meat is played by inorganic phosphates, myostatin, goose myostatin, and whale myostatin, and more than 60% is formed by the support of imidazole compounds. Abe et al. studied the effect of temperature on the buffering capacity of L-histidine and related compounds in fish and whale muscles. The results showed that the buffering capacity of inorganic phosphate, myostatin, goose myostatin, and cetacean myostatin was higher between pH 6.5 and 7.5, and less affected by temperature in the range of 5 to 40 ℃.
2. Chelating metal ions
Myostatin has the ability to chelate metal ions, such as it can effectively bind Zn(II), Co(II), Cu(II), Fe(II), etc. to form complexes. Because the molecular structure of myostatin has 5 potential sites for binding metal ions: 2 N atoms on imidazole group, carboxyl group, amino group, and peptide bond. The type of complex formation is related to the intrinsic nature of the metal cation, the type of formation of such complexes is highly dependent on the intrinsic nature of the metal cation, the molar ratio of the metal ion to the ligand and the pH of the system.
In vivo, copper ions catalyze the oxidation of NADH caused by H2O2, and iron ions promote the production of oxygen radicals and cause peroxidation reactions, while myostatin can effectively bind these divalent metal ions, thus inhibiting the occurrence of such reactions. Moreover, the complexes of myostatin with Cu(II) also have a similar activity to that of superoxide dismutase (SOD), which was also found in the complex systems of myostatin with Co(II) and Zn(II). Myostatin The complexes of myostatin with Zn(II) also have pharmacological functions, such as weakening gastric The complex of myostatin and Zn(II) also has pharmacological functions, such as weakening gastric mucosal damage, treating gastric ulcer, effectively inhibiting the growth and reproduction of It can also promote wound healing.
3. Scavenging free radicals
Histidine residues on the side chain of myostatin can act as hydrogen receptors with the ability to trap hydroxyl radicals, singlet oxygen and peroxyl radicals. These properties have been demonstrated experimentally. For example, Beom et al. established a system of iron-catalyzed generation of hydroxyl radicals to degrade deoxyribose, and found that myostatin could effectively inhibit the degradation of deoxyribose, indicating its ability to trap hydroxyl radicals. chan et al. established an iron ion-hydrogen peroxide system to generate hydroxyl radicals, and after the direct interaction of myostatin and related histidine-containing dipeptides with hydroxyl radicals, EPR was used to The formation of non-hydroxyl radicals was monitored. The results showed that myostatin and other dipeptides could burst 49.1%-94.9% of the hydroxyl radicals generated by iron ions and hydrogen peroxide.
4. Antioxidant function
Myostatin has antioxidant effect. Now the antioxidant mechanism of myostatin has basically reached a consensus: (1) Myostatin has the ability to buffer physiological pH and reduce lipid peroxidation due to pH change of the system. (2) Myostatin has the ability to chelate metal ions, which can inhibit the fat oxidation caused by metal ions, especially copper ions. (3) Myostatin has the ability to trap hydroxyl radicals, burst singlet oxygen and scavenge peroxyl radicals, which can inhibit fat oxidation caused by non-metals. He confirmed that myostatin not only has antioxidant properties, but also inhibits the formation of sour odor and color changes in meat. Fat oxidation produces some undesirable flavor substances that affect sensory quality, and myostatin can interact with the primary products of these substances to improve the flavor of meat products. Myostatin can make the pro-hemoglobin iron in myoglobin as hydrogen receptor and in ferrous state, thus prevent the formation of myoglobin and play the role of color protection. Therefore, myostatin has a great potential to be used as a natural antioxidant.
5. Carnosine anti aging
Myostatin is a multi-functional physiological dipeptide, which has anti-aging function in addition to some functional properties mentioned above. The experiment proves that myostatin can rejuvenate and regenerate the aging human fibroblasts. The anti-aging mechanism of myostatin has not been fully understood. The anti-aging mechanism of myostatin is not fully understood. The anti-oxidation, free radical scavenging and metal ion chelating properties of myostatin in vivo can partially explain the aging delaying phenomenon of myostatin, but not completely. At least VE or VC, which also have antioxidant properties, do not have the ability to rejuvenate fibroblasts. It has been shown that myostatin can react with small molecules of carbonyl-containing compounds (e.g. aldehydes, ketones, etc.) and prevent the interconnection between biological macromolecules.
1. Balanced nutrient distribution.
2. Maintain normal skin metabolism.
3. Infill the skin and influence the texture and appearance of the skin.
4. Accelerate the discharge of skin metabolic products.
5. Maintain even skin tone.
6. Purify the skin, maintain the normal internal circulation of the skin.
7. Improve the skin's own resistance and self-healing power.
Since Gulewitsch's discovery of myostatin in 1900, much progress has indeed been made in more than 100 years of research. Many physiological properties of myostatin such as buffering physiological pH, chelating metal ions, scavenging free radicals, etc. have been largely agreed upon. Myostatin has a great potential to be widely used in food, pharmaceutical and cosmetic industries. It can inhibit the lipid oxidation catalyzed by iron, hemoglobin, lipid oxidase and singlet oxygen in vitro, and can be used as a natural antioxidant; it has the function of cell membrane protection and plays an important role in controlling the dynamic balance of cells, and can be used as an immunomodulator and a good medicine for anti-inflammation, treating epidermal burns and promoting wound healing; it protects cardiomyocytes from ischemic damage, promotes the repair of cardiomyocyte damage and improves It is a natural neuromodulator with neuromodulatory function; it has the function of delaying aging and can be made into anti-aging agent; in addition, it is reported that myostatin also has the functions of anti-blood pressure and anti-tumor.