Plasmaglykoprotein

Plasmaglykoprotein is a type of glycoprotein found in the plasma of various organisms, including humans. It is a component of the complement system, a part of the immune system that helps to identify and neutralize foreign substances, such as bacteria and viruses. Plasmaglykoprotein is produced by the liver and is involved in the activation of the complement cascade, which leads to the lysis of pathogens and the clearance of immune complexes.

The structure of plasmaglykoprotein consists of a single polypeptide chain with a molecular weight of approximately 110 kDa. It contains multiple carbohydrate chains attached to asparagine residues, which contribute to its overall size and function. The protein has a globular shape and is composed of three domains: an N-terminal domain, a central domain, and a C-terminal domain.

Plasmaglykoprotein plays a crucial role in the regulation of the complement system. It can bind to the C1q component of the classical pathway of complement activation, enhancing the binding of C1q to immune complexes. This binding can lead to the activation of the complement cascade and the subsequent lysis of pathogens. Additionally, plasmaglykoprotein can inhibit the activity of the complement regulatory proteins, such as factor H and factor I, thereby prolonging the activation of the complement cascade.

Plasmaglykoprotein levels in the plasma can be elevated in certain pathological conditions, such as systemic lupus erythematosus and rheumatoid arthritis. In these conditions, the increased levels of plasmaglykoprotein can contribute to the activation of the complement system and the development of tissue damage. Therefore, plasmaglykoprotein is an important biomarker for the diagnosis and monitoring of these diseases.