This article will focus on the indispensable enzyme found in the stomach of every mammal, including humans. General information about the enzyme pepsin, information on its isomers and the role of the substance in digestion will be considered.
General views
First, let's find out which class of enzymes pepsin belongs to. This will allow a deeper understanding of the topic itself.
The enzyme pepsin belongs to the proteolytic class hydrolases and is produced by the gastric mucosa, and its main task is to break down the proteins received with food products into peptides. Pepsin is an enzyme that breaks down proteins in an acidic environment. It is produced by organisms of all mammals, as well as reptiles, representatives of the class of birds and many fish.
The presented enzyme is a globular type protein , has a molecular weight of approximately 34500. The molecule itself is presented as a polypeptide chain and consists of three hundred and forty amino acids. It also contains HPO3 and three disulfide bonds.
Pepsin is widely used in medicine and cheese making. In laboratories, it is used for the purpose of a more detailed study of protein compounds, namely, the primary protein structure. Pepsin has a natural inhibitor - pepstatin.
Enzyme variety
Pepsin has twelve isoforms. The differences between all pepsin isomers are electrophoretic motor ability, inactivation conditions, proteolytic activity. Pepsin code - CF 3. 4. 23. 1.
A person has seven types of pepsin in the juice of his stomach, 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 increased to 6, it is inactivated.
2. Pepsin 2 (B) is maximally active in pH = 2.1.
3. Type 3 shows the highest degree of activity at pH = 2.4–2.8.
4. Type 5, also known as gastricin, has the highest degree of activity at pH = 2.8–3.4.
5. Type 7 at pH = 3.3-3.9 has the highest activity.
The value of the enzyme in digestion
Pepsin is secreted by the gastric glands in a deactivated form (pepsinogen), and hydrochloric acid activates the enzyme itself. Under its influence, he goes into a healthy form. A prerequisite for the activity of the pepsin enzyme is the presence of an acidic environment, which is why when pepsin passes into the duodenum, it loses its activity, since the intestine is alkaline. The enzyme pepsin occupies one of the key roles 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 production of this enzyme varies. In men, about twenty to thirty grams of pepsin per hour is excreted, while in a woman, twenty to thirty percent less. The main cells, the sites of pepsin production, secrete it in the non-working form of pepsinogen. After cleavage of a certain amount of peptides from the N-terminus, pepsinogen enters the active form. The catalyst in this reaction of chemical transformations is hydrochloric acid. Pepsin has protease and peptidase properties and is responsible for protein disaggregation.
Medical business
In medicine, pepsin is widely used as a medicine for some diseases associated with the lack of production of this enzyme in the patient’s stomach. The rennet pepsin is obtained from the porcine mucous membranes of the stomach. The drug is available in the form of tablets, arranged in blisters, with an admixture of acidin or in the form of powders. Pepsin is part of some combination medicines. Has an ATC code A09AA03. An example of a pathology in which pepsin-containing medications are prescribed is Menetrier’s disease.
Beef Pepsin is ...
Rennet beef pepsin is one of the known and most commonly used forms of this substance. The enzyme itself is produced in the fourth stomach of the calf. The drug used in production is formed by two enzymes: pepsin and chymosin in natural proportional amounts. Rennet is used in cheese making, and its main functions are the formation of a clot of milk and participation in the maturation process of cheese and curd products.
Beef pepsin is secreted from the stomachs of cattle and, in the manufacture of products for sale, goes through two stages of purification of the enzyme from fat and impurities that are insoluble. The manufacturing process of beef pepsin goes through several stages: extraction process, salting out and freeze-drying.
Other applications
The pepsin enzyme is added to the sourdough. It is also used in cheese making. Rennet pepsin paired with chymosin form the same enzyme used to curdle milk.
The process of milk folding is called its protein 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 type of coagulation of the protein itself. The complex of pepsin with chymosin, in fact, is responsible for breaking the same bond and leads to the curtailment of milk.
Conclusion
Summing up, we can say that this biological 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 things. In production and medicine, the substance is mainly used as a medicine and is added to the rennet for the production of dairy and cheese products.