In this article we will talk about the indispensablean enzyme located in the stomach of each mammal, including a human. General information about the pepsin enzyme, information on its isomers and the role of the substance in digestion processes will be considered.
General views
First, let's find out which class of enzymes pepsin belongs to. This will allow you to better understand the topic itself.
The enzyme pepsin refers to hydrolasesproteolytic class and is produced by the gastric mucosa, and its main task is the cleavage of proteins supplied with food products to peptides. Pepsin is an enzyme that breaks down proteins in an acidic environment. It is produced by the organisms of all mammals, and also reptiles, representatives of the class of birds and many fish.
Представленный фермент относится к белкам globular type, has a molecular weight of approximately 34,500. The molecule itself is represented as a polypeptide chain and consists of three hundred forty amino acids. In its composition also contains HPO3 and three disulfide bonds.
Пепсин широко применяется в лечебном деле и cheese making. In laboratories it is used for the purpose of more detailed study of protein compounds, namely, the primary protein structure. Pepsin has a natural inhibitor - pepstatin.
Variety of enzyme
Pepsin has twelve isoforms.The differences between all pepsin isomers are in electrophoretic motor ability, inactivation conditions, proteolytic activity. The code of pepsin - KF 3. 4. 23. 1.
In humans, the juice of the stomach contains seven types of pepsin, and five of them sharply diverge in some qualities:
1. Actually pepsin (A) has a maximum activity in the medium pH = 1.9, and when raised to 6 it is inactivated.
2. Pepsin 2 (B) is maximally active in a pH = 2.1 environment.
3. Type 3 shows the highest degree of activity at pH = 2.4–2.8.
4. Type 5, also known as gastriksin, has the highest degree of activity at pH = 2.8–3.4.
5. Type 7 with pH = 3.3-3.9 has the highest activity.
The value of the enzyme in digestion
Pepsin is secreted by the gastric glands indeactivated form (pepsinogen), and the work of the enzyme itself is activated by hydrochloric acid. Under its influence, it turns into a workable form. A prerequisite for the activity of the enzyme pepsin is the presence of an acidic medium, which is why it loses its activity when pepsin passes into the duodenum, because it is alkaline in the intestine. The enzyme pepsin occupies a key role in the digestion of the entire class of mammals, and in particular humans. This substance breaks down food proteins into smaller peptide chains and amino acids.
In men and women, the indicators for making thisenzyme vary. Men have about twenty to thirty grams of pepsin per hour, while women have twenty to thirty percent less. The main cells, pepsin production sites, secrete it in the non-working form of pepsinogen. After the removal of a certain amount of peptides from the N-terminus, the pepsinogen passes into the active form. The catalyst in this reaction of chemical transformations is hydrochloric acid. Pepsin has protease and peptidase properties and is responsible for the disaggregation of proteins.
Therapeutics
In medicine, pepsin is widely used asmedicines for certain diseases associated with a lack of production of this enzyme in the stomach of the patient. Rennet rennet is produced from peptic porcine mucous membranes of the stomach. The drug is available in the form of tablets, spread on blisters, mixed with acidide or in the form of powders. Pepsin is also found in some combination drugs. It has a PBX code A09AA03. An example of the pathology in which pepsin-containing medications are prescribed is Menetria disease.
Beef pepsin is ...
Rennet bovine pepsin - one ofmost commonly used forms of this substance. The enzyme itself is produced in the fourth calf stomach. The drug used in production is formed by two enzymes: pepsin and chymosin in natural proportional amounts. Rennet is used in cheesemaking, and its main functions are the formation of a milk clot and participation in the process of ripening cheese and curd products.
Beef pepsin is released from the stomachs of a largecattle and in the manufacture of products for sale, undergoes two stages of purification of the enzyme from fat and impurities, which are insoluble. The process of making beef pepsin goes through several stages: the extraction process, salting out and freeze drying.
Other applications
The enzyme pepsin is added to the starter. It is also used in cheese making. Rennet pepsin paired with chymosin form the same enzyme used to fold milk.
The process of folding milk called himprotein coagulation, namely casein, with the formation of a milk-based gel. Casein has a specific structure, and only one peptide bond is responsible for the enzymatic coagulation type of the protein itself. The pepsin complex with chymosin is actually responsible for breaking the bond itself and leads to the folding of milk.
Conclusion
Summarizing, we can say that it isBiological active substance is one of the most important enzymes involved in the digestion of food in the stomach in representatives of many classes of living beings. In production and medicine, the substance is mainly used as a medicine and is added to rennet for the production of dairy products.
