C4b Human
Human Plasma.
Complement C4-B, Basic complement C4, C3 and PZP-like alpha-2-macroglobulin domain-containing protein 3, C4B, CO4, CPAMD3.
Sterile filtered solution.
Greater than 90.0% as determined by SDS-PAGE.
Description
Human Complement C4b produced in Human plasma is a glycosylated polypeptide chain containing 3 disulfide-linked chains and having a molecular mass of 195 kDa.
Product Specs
C4b, a key component of the complement system, is generated when C4 is cleaved. This cleavage, often facilitated by proteases like C1s in the classical pathway, releases C4a and activates C4b. Crucial for both the classical and lectin pathways, C4b, once activated, contributes significantly to the complement cascade. Interestingly, while humans possess both C4A and C4B variants, many animals typically have only C4B.
Human Complement C4b, produced from human plasma, is a complex glycoprotein with a molecular weight of 195 kDa. Its structure consists of three polypeptide chains interlinked by disulfide bonds.
The product is a clear, sterile solution that has been passed through a filter to remove any bacteria or particulate matter.
The C4b protein solution is buffered in a solution of 10mM Sodium phosphate and 145mM NaCl, maintaining a physiological pH of 7.3.
For short-term storage (2-4 weeks), C4a Human can be kept at refrigerated temperatures (4°C). For extended storage, freezing below -20°C is recommended. The addition of a carrier protein such as HSA or BSA (0.1%) is advised for long-term storage. Repeated freezing and thawing of the product should be avoided.
The purity of the C4b protein is determined using SDS-PAGE analysis and is consistently found to be greater than 90%.
Stringent viral testing is performed on the plasma used in the production process. Each donor's plasma is screened and confirmed negative for antibodies against HIV-1, HIV-2, HCV, and HBSAG, ensuring product safety.
Complement C4-B, Basic complement C4, C3 and PZP-like alpha-2-macroglobulin domain-containing protein 3, C4B, CO4, CPAMD3.
Human Plasma.
Product Science Overview
Complement C4 is a protein encoded by the C4B gene in humans . The C4 protein is initially synthesized as a single-chain precursor, which is then cleaved into three chains: alpha, beta, and gamma. These chains form a trimer that is essential for the protein’s function. The alpha chain can be further cleaved to release C4 anaphylatoxin, a mediator of local inflammation .
C4b is generated when C4 is cleaved by the enzyme C1s, which is part of the C1 complex in the classical pathway. The cleavage of C4 releases C4a (an anaphylatoxin) and C4b. The C4b fragment then binds covalently to the surface of pathogens or cells, marking them for destruction by other components of the immune system .
The C4B gene is located on chromosome 6 within the major histocompatibility complex (MHC) class III region . This region is highly polymorphic, meaning there is a significant amount of genetic variation among individuals. These variations can affect the number of C4B gene copies, leading to differences in the levels of C4b protein produced. Some individuals may have one, two, or even three copies of the C4B gene .
Deficiencies or mutations in the C4B gene can lead to a variety of immune-related disorders. For example, a deficiency in C4b is associated with systemic lupus erythematosus (SLE), an autoimmune disease where the immune system attacks the body’s own tissues . Other conditions linked to C4b deficiencies include type 1 diabetes and certain types of encephalitis .
Research into the genetic variability of C4b and its role in disease has significant clinical implications. Understanding the polymorphisms and gene copy number variations can help in diagnosing and treating autoimmune and inflammatory diseases. For instance, identifying specific mutations or deficiencies in the C4B gene can lead to targeted therapies that address the underlying genetic causes of these conditions .
