Inhibitor

An inhibitor is a substance that blocks chemical reactions, biological reactions (including immune reactions), and biological activities. Currently commonly used inhibitors include: immunosuppressants and enzyme inhibitors. 1. Immunosuppressants: Immunosuppressive drugs that lower the immune response. It can selectively act on certain immune reaction links and immune cells required for inhibition. Immunity refers to the body's response to various pathogenic substances. Some of these reactions are beneficial to the body and can enhance the body's disease resistance. Some are unfavorable to the body and can cause physiological disorders or tissue damage (allergy). Therefore, the immune response of the body is reduced by applying an immunosuppressive agent to an allergic reaction to the body to affect the immune process. In order to treat various immune diseases and to attenuate tissue incompatibility, various immunosuppressive agents have been developed, some of which have been widely used in the clinic. Commonly used immunosuppressive agents are glucocorticoids (prednisone, prednisolone, etc.), alkylating agents (nitrogen oxide mustard, cyclophosphamide, thiotepa, busulfan, etc.), antimetabolites (6- Mercaptopurine, azathioprine, methotrexate, etc.). Although the mechanism of action of immunosuppressive agents is not completely clear, it has the following characteristics: 1 Most immunosuppressive agents can inhibit both cellular immunity and humoral immunity, and can be used for organ transplantation and autoimmune diseases. 2 The inhibitory effect on the primary immune response is strong, and the effect on the re-immune response is weak. 3 can act on both pathological and normal immunity, and therefore often leads to certain complications. 4 These drugs are highly toxic and have serious adverse reactions. 2. Enzyme inhibitor: An enzyme inhibitor is a compound or drug that binds to an enzyme and inhibits the catalytic activity of the enzyme. Clinically, an enzyme inhibitor specifically interferes with a metabolic system to achieve therapeutic goals. For example, a monoamine oxidase inhibitor used as an antidepressant, a carbonic anhydrase inhibitor used as a diuretic, a dopa decarboxylase inhibitor for antihypertensive drugs, and a penicillin or cephalosporin belonging to a cell wall synthetase inhibitor among antibiotics. Classes, etc. It is also used in veterinary medicine and agriculture. In addition, enzyme inhibitors can also be used to study the mechanism of action and metabolic pathways. The structure of the enzyme inhibitor is often similar to the structure of its natural substrate. According to the modification of the natural substrate design inhibitor, the first step is to analyze and determine the function of each part of the molecule when combined with the enzyme, whether it is a combination, whether it is repulsive or not related to the binding. Secondly, the degree of tolerance of the binding site to adjacent steric hindrance is known. Each functional group is then substituted to regulate the strength of interaction with the enzyme. Enzyme inhibitors can be divided into two major categories of reversible and irreversible. (1) An inhibitor that binds to an enzyme through a non-covalent bond is a reversible inhibitor. (2) The inhibitor that binds to the enzyme through the covalent bond is an irreversible inhibitor, and the binding is very tight, and is not affected by changes in concentration such as dialysis or dilution after binding with the enzyme.