What Is Enzymology?

enzymology

Enzymology

(Branch subject)

enzymology

the study

Advances in enzymology have been countless since the discovery of photosynthesis in 1771

The most representative of enzymatic production of daily chemicals is the production of acrylamide by bacterial nitrile hydratase. Acrylamide is a water-soluble monomer of vinyl series polymers, which is formed by the hydration reaction of acrylonitrile. Acrylamide polymers are also water-soluble, and are widely used as raw materials for functional polymers such as paper reinforcing agents, polymer flocculants, petroleum recovery agents, and the like. The gel formed by acrylamide cross-linking polymerization has very strong water absorption, which is expected to be used in horticulture and desert greening to promote plant growth.

Bioactive peptides, especially oligopeptides,

1. Definition of enzymes: Enzymes are biocatalysts produced by living cells. They are proteins in nature and have a highly specific and efficient catalytic effect.

2. The difference between enzyme and general catalyst:

High efficiency: Under normal temperature and pressure and neutral pH conditions, the enzyme has 107 ~ 1013 times higher catalytic efficiency than ordinary catalysts.

High specificity: There are three types of specificity from the different molecular structure requirements of enzymes:

(1) Absolute specificity;

(2) Relative specificity;

(3) Specificity of stereoisomerism.

Instability and adjustability: Enzymes are proteins, and all factors that cause protein denaturation can also inactivate enzyme denaturation. At the same time, the catalytic action of enzymes can be regulated by a variety of factors, thereby changing its catalytic activity, especially some key enzymes in the metabolic process, which are often important regulatory objects.

1. The molecular composition of the enzyme:

According to different chemical composition, it can be divided into two categories: simple protease and bound protease. Simple protease molecules contain only amino acids; in addition to protein (becoming an enzyme protein), bound protease molecules also contain a non-protein part, which is often called a "cofactor" and a protein part called "enzyme protein". "Enzyme", all enzymes have catalytic activity.

Cofactors can be metal ions or small molecule organic compounds. The latter can be divided into coenzymes and prosthetic groups depending on how tightly they bind to the enzyme protein. Coenzyme refers to a small molecule organic matter that is non-covalently bound to an enzyme protein. Because it is loosely bound, the two can be separated by dialysis, which is the most common among binding enzymes. Prosthetic groups refer to small molecular organic compounds that bind tightly (usually covalently) to enzyme proteins, so they cannot be separated by dialysis. Coenzymes (bases) often contain B vitamins.

In binding enzymes, the specificity of enzyme catalysis is determined by the enzyme protein part; the role of coenzyme coenzyme is to transfer groups, atoms and electrons in the reaction. The role of metal ions is: some are necessary to stabilize the conformation of the enzyme protein molecule, some constitute the active center of the enzyme; some serve as a bridge between the enzyme and the substrate, and some neutralize the anion to reduce the electrostatic repulsion in the reaction.

2. The active center of the enzyme:

The group required for the enzyme to play a catalytic role is called an essential group. Generally refers to the polar group distributed on the surface of the enzyme molecule, including -COOH, -NH2, -OH, -SH, imidazolyl and the like.

These essential groups are relatively concentrated on the surface of the enzyme molecule, and the space region that participates in the enzyme and substrate to form a complex and catalyzes the reaction is called the active center of the enzyme.

The necessary groups of the active center include a binding group (bound to a substrate) and a catalytic group (catalytic substrate to product). There is also an essential group outside the active center, which is also necessary in the formation of the spatial conformation of the enzyme, so it is called an essential group outside the active center.

The structure of the active center of different enzyme molecules is different, and it can only combine certain substrates suitable for it to produce a certain chemical reaction, so the specificity of the catalytic action of the daughter enzyme is explained based on the structure.

3. Enzyme and zymogen activation:

Many proteolytic enzymes are only inactive precursors of enzymes, namely zymogens, when they are synthesized or initially secreted in cells. Such as protease secreted by the digestive glands. The enzymes involved in blood coagulation and the enzymes that dissolve fibrin clot exist in the form of zymogen, and need to be processed before they can function. That is, under certain conditions, the zymogen is converted into an active enzyme, which is called zymogen activation. The process of zymogen activation is usually to remove some peptides in the zymogen molecule, which is conducive to the formation of the active center of the enzyme.

Taking trypsinogen activation as an example, the activation mechanism and the clinical significance of some enzymes in the form of zymogen are explained.

4. Polymorphism of enzyme:

(1) Isoenzymes: refers to a group of enzymes that can catalyze the same chemical reaction but the molecular structure of the enzyme protein is different.

Has the following characteristics:

a. Exist in different components of the same genus or same individual or in the same cell of the same tissue.

b. Different primary structures, physical and chemical properties including different charged properties, and different immunological properties, but the active centers in the spatial structure are the same or similar

c. Enzymes that are often quaternary.

d. More than one hundred enzymes have been found to have isozyme properties. It was discovered that the earliest research was lactate dehydrogenase, which has five isoenzymes. Isoenzyme changes in clinical assays are mostly used in the diagnosis and differential diagnosis of diseases.

(2) Defective enzyme molecules