This article will focus on an essential enzyme found in the stomach of every mammal, including humans. General information about the enzyme pepsin, information about its isomers and the role of the substance in digestion processes will be considered.
General Views
First, let's find out what class of enzymes pepsin belongs to. This will allow you to delve deeper into the topic itself.
The enzyme pepsin belongs to the proteolytic class of hydrolases and is produced by the gastric mucosa, and its main task is to break down proteins from food into peptides. Pepsin is an enzyme that breaks down proteins in an acidic environment. It is produced by the organisms of all mammals, as well as reptiles, representatives of the class of birds and many fish.
The presented enzyme belongs to globular type proteins, has a molecular weight of approximately 34500. The molecule itself is presented in the form of 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. Differences between all pepsin isomers are in electrophoretic motor ability, inactivation conditions, and proteolytic activity. Pepsin code - KF 3. 4. 23. 1.
Human stomach juice contains seven types of pepsin, and five of them differ sharply in some qualities:
1. Actually, pepsin (A) has the maximum activity in the medium pH=1.9, and with an increase to 6 it is inactivated.
2. Pepsin 2 (B) is maximally active in the medium pH=2.1.
3. Type 3 shows the highest degree of activity at pH=2.4–2.8.
4. Type 5, also known as gastrixin, has the highest degree of activity at a pH of 2.8–3.4.5. Type 7 at pH=3.3-3.9 has the highest activity.
Importance 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 workable 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 environment in the intestine is alkaline. The enzyme pepsin occupies one of the key roles in the digestion of the entire class.mammals, and in particular humans. This substance breaks down food proteins into smaller peptide chains and amino acids.
Men and women have different levels of this enzyme. Men excrete about twenty to thirty grams of pepsin per hour, while women have twenty to thirty percent less. The basal cells, 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 passes into its active form. Hydrochloric acid acts as a catalyst in this chemical transformation reaction. Pepsin has protease and peptidase properties and is responsible for the disaggregation of proteins.
Medicine
In medicine, pepsin is widely used as a medicine for some diseases associated with a lack of production of this enzyme in the patient's stomach. The rennet enzyme pepsin is obtained from the 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 also part of some combined drugs. It has ATC code A09AA03. An example of a pathology in which pepsin-containing drugs are prescribed is Menetrier's disease.
Beef pepsin is…
Beef rennet pepsin is one of the well-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 proportions. Rennet is used in cheese making, and its main functions are the formation of a clot of milk and participation in the process of maturation of cheese and curd products.
Beef pepsin is extracted 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 process of making beef pepsin goes through several stages: extraction process, s alting out and freeze drying.
Other applications
The enzyme pepsin is added to the sourdough. It is also used in cheese making. The rennet enzyme pepsin paired with chymosin form the same enzyme used to curdle milk.
The process of curdling milk 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 protein folding. The complex of pepsin with chymosin is actually responsible for breaking that very bond and leading to milk curdling.
Conclusion
Summarizing, we can say that this biologically active substance is one of the most important enzymes involved in the digestion of food in the stomach of representatives of many classes of living beings. In manufacturing and medicine, the substance is mainly used as medicine andadded to rennet for the production of dairy and cheese products.
