C3d Human
Human Plasma.
Complement C3, C3 and PZP-like alpha-2-macroglobulin domain-containing protein 1, C3, CPAMD1.
Sterile filtered solution.
Greater than 95.0% as determined by SDS-PAGE.
Description
Human Complement C3d produced in Human plasma having a molecular mass of 33.8kDa.
Product Specs
C3d, a fragment of the complement protein C3, is generated through a series of proteolytic cleavages of human C3. The production of C3d involves purifying human C3 and converting it to C3b using the natural human C3 convertase. C3b is then transformed into iC3b, which undergoes trypsin cleavage to yield C3d. During complement activation, if C3b is bound to a surface, the resulting iC3b, C3dg, and C3d fragments remain covalently attached. It's important to note that C3d can only bind to a surface during complement activation. The attachment of surface-bound C3d to the target occurs through an ester or amide covalent bond. However, ester bonds are inherently unstable, leading to the release of C3d from the particle.
Human Complement C3d, derived from human plasma, has a molecular weight of 33.8 kDa.
The product is provided as a sterile filtered solution.
The C3d solution is formulated in phosphate buffered saline at a pH of 7.2.
For short-term storage (2-4 weeks), C3d Human remains stable at 4°C. For extended storage, it is recommended to freeze the product below -20°C. To further enhance long-term stability, adding a carrier protein (0.1% HSA or BSA) is advisable. It's crucial to avoid repeated freeze-thaw cycles to maintain product integrity.
The purity of the product exceeds 95.0%, as determined by SDS-PAGE analysis.
Each plasma donor undergoes rigorous testing to ensure the absence of antibodies against HIV-1, HIV-2, HCV, and HBsAG. Only plasma samples that test negative for these viruses are used in the production process.
Complement C3, C3 and PZP-like alpha-2-macroglobulin domain-containing protein 1, C3, CPAMD1.
Human Plasma.
Product Science Overview
Complement C3d is a fragment of the complement component 3 (C3), which plays a crucial role in the immune system. The complement system is a part of the innate immune response and is involved in the defense against pathogens. C3d is generated during the activation of the complement system and has significant implications for both innate and adaptive immunity.
Complement C3 is a large protein composed of multiple domains. Upon activation, C3 is cleaved by C3 convertases into C3a and C3b. C3b can further be degraded into iC3b and then into C3dg and C3d . C3d is a 33 kDa polypeptide fragment that retains the thioester bond, allowing it to covalently attach to pathogen surfaces .
C3d plays a dual role in the immune system:
- Innate Immunity: C3d can bind to pathogen surfaces, marking them for destruction by phagocytes. This process is known as opsonization. The covalent attachment of C3d to pathogens enhances their recognition and clearance by immune cells .
- Adaptive Immunity: C3d is also involved in the activation of B cells. It binds to complement receptor 2 (CR2) on B cells, forming a complex with antigen-specific immunoglobulins. This interaction lowers the threshold for B cell activation, promoting a more robust antibody response .
The complement system is an ancient defense mechanism, present in species that have existed for over 600 million years . The interaction between C3d and CR2 represents a link between innate and adaptive immunity, which is a more recent evolutionary adaptation. This interaction has evolved to optimize the dual functionality of C3d, allowing it to participate in both pathogen recognition and B cell activation .
C3d is involved in various clinical conditions. It plays a role in the regulation of immune responses and the induction of tolerance. Pathogens and cancer cells can exploit this mechanism to evade the immune system by inhibiting complement activation . Understanding the role of C3d in these processes can provide insights into the development of therapeutic strategies for immune-related diseases.
