Magical Peptides and Their Functions (II)

• Posted by Samantha James September 29, 2020 Filed in Arts & Culture 229 views
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  Main applications

  At present, the application of functional peptides is mainly in the following aspects:

  1. Functional foods: peptide foods with certain functions are currently a hotspot in international research. Japan, the United States, and Europe have taken the lead in launching food and food additives with various functions, forming an industry with great commercial prospects.

  2. Peptide reagents: very high purity, mainly used in scientific tests and biochemical tests, and the price is very expensive.

  3. Peptide drugs.

  4. Feed and feed additives: The research on functional peptides in the feed industry started with antimicrobial peptides, but the birth of "pure milk peptide" opened the prelude to a large-scale comprehensive study of functional peptides in the feed industry. It provides phospholipid-containing peptides that are used in cell membranes. The main ingredient, after being quickly absorbed and transformed, has the function of repairing intestinal damage immediately, and it is rich in small peptides, which can be absorbed by the suckling pig's intestine without obstacles. It is an optimal feed material to replace high-grade animal protein such as plasma. Its intestinal repair function has great application value in the era of anti-resistant feed.

  Classified by physiological function

  According to their functions, functional peptides can be roughly divided into physiological functional peptides, flavoring peptides, antioxidant peptides, and nutritional peptides. However, because some peptides have multiple physiological activities, this classification is only relative.

  This chapter mainly introduces the basic concepts and physiological functions of physiologically active peptides and regulatory peptides.

  Physiological functional peptides are important chemical messengers that communicate information between cells and organs. Through endocrine and other action methods, the body forms a highly rigorous control system to regulate growth, development, reproduction, metabolism and behavior and other life processes. These polypeptides are commonly referred to as physiological functional peptides. It mainly has the following types:

  1. Binding peptides: Most mineral element binding peptides contain phosphorylated serine groups and glutamyl residues at the center, and the binding sites for mineral elements are on the side of the negatively charged side chains of these amino acids, the most obvious is characterized by containing phosphoric acid groups. Binding to calcium requires a phosphate group containing serine and a free carboxyl group of glutamic acid. This combination can enhance the solubility of the mineral-peptide complex. Casein phosphopeptide (CPP) is currently the most studied mineral element binding peptide. It can combine with a variety of mineral elements to form a soluble organic phosphate, acting as many mineral elements such as Fe2+, Mn2+, Cu2+, Se2+, especially Ca2+. The transport carrier in the body can promote the absorption of Ca2+ and other mineral elements in the small intestine. The casein phosphopeptide has a serine phosphorylation structure in the molecule and has a significant effect on calcium absorption. It is a natural physiological functional peptide separated from milk protein by applying biotechnology. It exists in cow's milk casein and has two substances. The α-casein phosphopeptide made of α-casein is a phosphopeptide composed of 37 different amino acids, including 7 serines combined with phosphate groups, with a molecular weight of 46,000. The β-casein phosphopeptide made of β-casein is a phosphopeptide composed of 25 different amino acids, including 5 serines combined with phosphate groups, with a molecular weight of 3100. Casein phosphopeptide is a type of polypeptide containing 25 to 37 amino acid residues, which can effectively form a soluble complex with calcium at pH 7 to 8.

  2. Phosphopeptides: Physiological functions mainly include the following aspects: (1) Promote the development of bones and teeth in growing children; (2) Prevent and improve osteoporosis; (3) Promote the rehabilitation of fracture patients; (4) Prevent and improve iron deficiency anemia; (5) anti-caries. Japan, Australia, Germany, etc. apply it to functional foods, such as calcium and iron supplements with casein phosphopeptides in Japan, including liquid beverages, fortified dairy products, biscuits, cakes, and candies.

  3. Related reagents: this type of peptides include glutathione, incretin, etc. Glutathione can be completely absorbed in the small intestine. It can maintain the integrity of the red blood cell membrane. It has the function of protecting and restoring the activity of enzymes that require sulfhydryl groups. It is the coenzyme or prosthetic group of various enzymes and can participate in the absorption of amino acids. Glutathione (GSH) is a tripeptide compound formed by the condensation of glutamic acid, cysteine ​​and glycine through peptide bonds. It is widely present in animal liver, blood, yeast and wheat germ, various vegetables and other plant tissues. Glutathione has a unique physiological function and is called a longevity factor and anti-aging factor. Japan began to develop and apply it to food in the 1950s and has now been widely used in the field of food processing. The production methods of glutathione mainly include solvent extraction, chemical synthesis, microbial fermentation, and enzyme synthesis. Among them, the use of microbial cells or enzymes to biosynthesize glutathione has great potential for development. At present, yeast fermentation is the main method to produce glutathione. Glutathione plays an important role in the organism: (1) As an antidote, it can be used to detoxify acrylonitrile, fluoride, CO, heavy metals and organic solvents. (2) As a free radical scavenger, it can protect cell membranes from oxidative damage, prevent red blood cell hemolysis and promote the reduction of methemoglobin. (3) Play a protective effect on leukopenia. (4) It can correct the imbalance of acetylcholine and cholinesterase and play an anti-allergic effect. (5) It can relieve discomfort caused by hypoxemia, nausea and liver disease.It can prevent skin aging and pigmentation, reduce the formation of melanin, improve the skin's antioxidant capacity and make the skin glow.

  To be continued in Part III…