C1Q Rat
Rat Plasma.
Component C1q, Complement C1q, Complement Component C1q, C1q.
Sterile filtered solution.
Greater than 93.0% as determined by SDS-PAGE.
Description
Rat Complement C1Q produced in Rat plasma having a molecular weight of 400kDa.
Product Specs
Complement component 1q (C1q) initiates the classical complement pathway, a crucial part of the immune system. C1q, C1r, and C1s form the C1 complex. When C1 binds to immune complexes, C1r and C1s activate, triggering the complement cascade. C1q, a 410-462 kDa glycoprotein in the collectin family, consists of six globular heads connected to collagen-like tails. The globular heads specifically bind to the CH2 domain of IgG or the CH3 domain of IgM. Activation requires C1q binding to at least two immunoglobulin heavy chains, ensuring activation only occurs with immune complexes. C1q primarily clears immune complexes and apoptotic cells, preventing autoimmunity. Deficiencies in C1q or other classical pathway components can lead to autoimmune diseases like SLE. C1q binds to apoptotic cells like keratinocytes, endothelial cells, and lymphocytes, promoting their removal by complement-mediated mechanisms. This process helps clear potential autoantigens, preventing immune system activation. However, prolonged exposure to C1q bound to immune complexes or apoptotic cells may trigger an autoimmune response against C1q, disrupting complement function. C1q deficiency can also impair the removal of autoreactive B cells. C1q, along with other recognition molecules, binds to lupus antigens (dsDNA and nuclear proteins), activating the complement system. Autoantibodies against C1q (anti-C1q) are found in autoimmune and infectious diseases like glomerulonephritis and lupus erythematosus. These antibodies are clinically significant due to their negative predictive value.
Rat Complement C1Q is a 400 kDa protein produced from Rat plasma.
The product is a sterile, filtered solution.
The C1Q solution is formulated in 10mM HEPES buffer with 300mM NaCl, at pH 7.2.
Rat C1Q remains stable at 4°C for 2-4 weeks, provided the entire vial is used within this period. For extended storage, freeze the product below -20°C. Adding a carrier protein (0.1% HSA or BSA) is recommended for long-term storage. Avoid repeated freezing and thawing of the product.
The purity of the Rat Complement C1Q is greater than 93%, as determined by SDS-PAGE analysis.
Component C1q, Complement C1q, Complement Component C1q, C1q.
Rat Plasma.
Product Science Overview
C1q is composed of six extended arms, each ending in a globular head. These heads can bind to the Fc regions of immunoglobulins, such as IgG or IgM, when they are part of immune complexes. This binding is essential for the activation of the complement system. When antibodies bind to antigens, forming immune complexes, they cluster together, allowing multiple arms of C1q to bind to the Fc regions of the antibodies .
The binding of C1q to immune complexes triggers the auto-activation of the C1r proteins within the complex. The activated C1r proteins then cleave and activate the C1s protease zymogens. Activated C1s cleaves complement component C4, releasing C4a and initiating the covalent attachment of C4b to the activating surface. This process continues with the cleavage of C2, forming the C3/C5 convertase of the classical pathway .
C1q plays a vital role in both innate and adaptive immunity. It interacts with various immunoglobulin and non-immunoglobulin activators of the complement system. Additionally, C1q is involved in the clearance of cell debris and the regulation of cellular events by interacting with a wide range of cell surface molecules .
The presence of collagen-like triple-helical structures within C1q is crucial for the presentation and multivalent binding of its globular heads to targets. This structure also facilitates its association with the proenzyme complex of C1r and C1s, forming the C1 complex. The movement of these collagen-like structures in the activation of the C1 complex remains a controversial area, with no definitive answer on how the first C1r proenzyme molecule becomes activated .
