Relaisson

　　How to snipe urease, the main pathogenic factor of Helicobacter pylori

　　Helicobacter pylori (Hp) bacteria contain a large amount of active urease in and out of the body. Urease is an important pathogenic factor of Hp infection. Therefore, a deep understanding of it has important practical significance for preventing and eradicating Hp infection.

　　Urease is an important pathogenic factor of Hp. This pathogenicity is mainly manifested in two aspects: On the one hand, urease enables Hp to "live in safety" in the human stomach; on the other hand, urease hydrolyzes urea to produce Ammonia uses ammonia or ammonium salts to directly damage host tissues and cells by raising the pH of a particular part of the host.

　　colonization

　　Hp wild strain can inhabit the gastric mucosa of gastric acid, but the stable ureB-mutant strain cannot, indicating that urease is one of the necessary conditions for Hp to colonize the gastric mucosa. This is because urease can catalyze the production of ammonia from urea, neutralize gastric acid, and create a neutral environment inside and outside the cell, so that the bacteria can survive in a strong acid environment for enough time, so that the bacteria can pass through the gastric mucus layer and inhabit. On the surface of gastric mucosal epithelial cells. Studies have also shown that Hp mutant strains that lose urease activity due to ureG mutations cannot be colonized in gastric mucosa with low gastric acid and normal gastric acid. When this mutant strain is co-cultured with wild plants, wild plants will preferentially colonize, which indicates that urea Enzymes must have other roles in the process of colonization.

　　The effect of damaging host tissue

　　Urease catalyzes the hydrolysis of urea to produce large amounts of ammonia. On the one hand, ammonia neutralizes gastric acid and up-regulates the pH value of the epithelial cell surface; on the other hand, ammonia itself is toxic and can also form some toxic substances with other components in the stomach, thereby directly or indirectly damaging host tissues. From the current research, urease mainly uses four behaviors to directly damage host tissues and cells.

　　Increased pH

　　Urease is covered with some protective film on the surface of epithelial cells. Ammonia will increase the pH value of its special parts, thereby impairing its integrity, as well as ion pump, ligand-receptor binding, enzyme receptor activity and other functions.

　　Ammonia has a direct attack effect on poisoning host tissues

　　Ammonia and water balance to produce hydroxyl groups, which directly cause host tissue damage; ammonia can also interfere with the infiltration of hydrogen ions through the gastric mucosa under normal conditions, thereby causing direct toxicity to epithelial cells.

　　Monochloramine induces canceration of host tissues

　　At present, Hp is a type I carcinogen of gastric cancer. When white blood cells, urea and Hp urease appear in the same reaction at the same time, monochloramine is formed. Monochloramine can induce mutations in host genes. It is a carcinogen associated with Hp infection.

　　ammonium chloride induced vacuole effect

　　Ammonia and gastric acid produce ammonium chloride which is highly toxic to cells. Studies have shown that wild-type Hp can cause cells to produce vacuoles, while urease-negative mutant strains cannot. Compared with the direct induction of vacuolar toxin and ammonia, it induces VagA to produce a vacuolar effect faster and produces larger vacuoles. This shows that in the process of damaging cells, there is a necessary cooperative relationship between urease and VagA.

　　So, how to change the enzyme activity of urease?

　　Urease is a nickel-containing metalloenzyme. The substitution and modification of metal ions in its enzyme molecule can significantly affect its enzyme activity.

　　The zinc in 　　RuiLaisheng is inserted through a special enzyme protein, which can change the conformation of urease, which causes its enzyme activity to drop by more than 90%.

　　Finally, it changes the external living environment of Hp and can affect its direct pathogenicity to achieve the effect of internal and external snipe urease.