Immunoglobulin G, why does he need a person?

Many factors respond to the fight against infection in the human body. One of the most important places in this process belongs to immunoglobulins, and to be more precise, immunoglobulin G. Among other types of immunoglobulins, it is Ig G that is able to protect the newborn's body from infections, as it has the ability to penetrate with the blood of the mother through the placenta, Blood flow of the child.

The Ig G molecule consists of a subunit whose weight is approximately 150 kD. In humans, as well as in mice, four subclasses that have immunoglobulin G are described. They were first detected using serological methods of investigation. The hinge region of immunoglobulins is characterized by a large number of residues of cysteine and proline molecules, which determines its flexibility. Disulfide bonds in this part of the molecule have their differences, starting from the subclass of globulin. So, Gamma 1 and Gamma 4 globulins have two disulfide bonds, Gamma 2 - four, Gamma 3 - eleven. In Gamma 1 chain, the hinge region originates only from the 216th residue, and ends at 231-m. And the hinge region of Gamma 3 of the chain is located forty-seven times later than Gamma 1. The study of this amino acid sequence makes it possible to assume that such an increase in residues is associated with a double duplication of the Gamma 1 chain sections 216-231. The hinge region has a significant feature: thanks to the interactions of the two heavy chains, a rigid and cyclic octapeptide structure arises that serves as the axis of rotation for the entire flexible hinge region, and therefore for the Fab fragments, which is extremely necessary for interaction with a variety of antigens.

Generation of IgG occurs during the primary and secondary immune response, since this type of antibody is extremely efficient to penetrate into tissues, binds and, subsequently, removes foreign antigens.

For antibacterial protection in the human body is responsible precisely immunoglobulin G. Increased this type of globulin can be in cases where the immune system has already come into contact with foreign antigens and began to actively develop their antibodies. Thus, the timely detection of an increase in the number of immunoglobulins allows us to begin timely diagnosis and treatment of diseases that cause a variety of bacteria and viruses.

The main function of this type of immunoglobulin is to protect the human body from foreign agents that can cause infectious diseases. Immunoglobulin G fights both with the pathogens themselves, and with the products of their vital activity by opsonization, the launch of phagocytosis systems and a compliment.

Immunoglobulin G is a thymus dependent, that is, it is synthesized in the thymus (thymus), with the direct involvement of T-lymphocytes. This type of globulin is the main component of the globulin fraction of the blood and accounts for about 80% of all types of immunoglobulins. Thus, the use of all possible immunosuppressants, as well as irradiation in a state not only suppress the synthesis of Ig G, but also suppress it completely.

Immunoglobulin G, the norm of which in the body varies depending on age, reaches its final level by 15 years and is 8-17 grams per liter of blood. In this case, immunoglobulins are able to be not only in the vascular bed and circulate through the body together with blood, they can also easily enter the extravascular space, starting to perform all of their numerous functions. Immunoglobulin G is evenly distributed both in the vascular bed and inside the rest of the body tissues, so that the body is protected from infections.

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