Complement glycoprotein

CRP , complement , PLA2 , serum amyloid A , fibrinogen , c -acid glycoprotein , IL-1Ra , ceruloplasmin , ai-antichymotrypsin , LBP albumin , haptoglobin , IGF-1 , transferrin , u2-HS glycoprotein ... 

The three selectins are related both structurally and functionally. They are transmembrane proteins, with an N-terminal C-type actin domain, followed by an EGF repeat and a variable number of complement control protein (CCP) domains. Selectins bind carbohydrates, which are present in various glycoproteins. 

These proteins are called acute phase proteins (or reactants) and include C-reactive protein (CRP, so-named because it reacts with the C polysaccharide of pneumococci), ai-antitrypsin, haptoglobin, aj-acid glycoprotein, and fibrinogen. The elevations of the levels of these proteins vary from as little as 50% to as much as 1000-fold in the case of CRP. Their levels are also usually elevated during chronic inflammatory states and in patients with cancer. These proteins are believed to play a role in the body s response to inflammation. For example, C-reactive protein can stimulate the classic complement pathway, and ai-antitrypsin can neutralize certain proteases released during the acute inflammatory state. CRP is used as a marker of tissue injury, infection, and inflammation, and there is considerable interest in its use as a predictor of certain types of cardiovascular conditions secondary to atherosclerosis. Interleukin-1 (IL-1), a polypeptide released from mononuclear phagocytic cells, is the principal—but not the sole—stimulator of the synthesis of the majority of acute phase reactants by hepatocytes. Additional molecules such as IL-6 are involved, and they as well as IL-1 appear to work at the level of gene transcription. 

The acute-phase response is characterised by the enhanced (two- to threefold) synthesis of a number of proteins, such as antiproteinases, complement components, fibrinogen and ceruloplasmin, which are normally synthesised at fairly low rates. The rate of synthesis of some proteins is enhanced 100-1000-fold - for example, C-reactive protein, a-macroglobulin and acid-1-glycoprotein. Thus, serum levels of these proteins serve as indicators of disease. 

Complement. Complement is an extensive series of glycoproteins and protein inhibitors whose function includes major cytolytic effects, mediation of opsonization, and modulation of inflammatory responses. Activation of this system plays an important role in host defense leading to destruction of microorganisms. It also results in generation of anaphylotoxins which induce mediator release and "split products" that mediate membrane damage, either directly through structural alteration or indirectly, via cell chemotaxis and regulation. 

Medicinal thrombocytopenia can emerge under the use of different medicines, including interferon. The main mechanism of medicinal thrombocytopenia pathogenesis is assisted by the destruction of thrombocytes by the complement which is activated during antibody preparation. On withdrawal, the content of thrombocytes in blood is normalized. The formation of antibodies to thrombocytes in patients with viral hepatitis C occurs due to the destruction of membrane glycoproteins by the viruses. 

Manderson, G. A., Martin, M., Onnerfjord, P., Saxne, T., Schmidtchen, A., Mollnes, T. E., Heinegard, D., and Blom, A. M. (2009). Interactions of histidine-rich glycoprotein with immunoglobulins and proteins of the complement system. Mol. Immunol. 46, 3388-3398. 

Nonspecific staining can be caused by Fc receptor glycoproteins present on the cell membrane. This problem is more relevant to frozen sections and smears than to tissues fixed with formaldehyde. The problem can be avoided by using F(ab)2 fragments instead of whole IgG molecules (Boenisch, 2001). Complement-mediated binding may also cause background staining in frozen sections when whole antisera is used however, this problem is not very common. 

Nonspecific humoral immunity is mediated via the complement system. After activation of the complement system a cascade is initiated in which more than 15 individual glycoprotein compounds in the plasma react with each other in a... 

The glycoprotein Clq of the complement system binds to the Fc regions of two antibodies which must have previously formed a Fc dimer. 

Cubilin is a glycoprotein with a molecular weight of460 kDa (A1, K21) with 27 CUB domains (subunits of complement Clr/Cls, epidermal growth factor (EGF),... 

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