C1R Human
Human Plasma.
Complement C1r subcomponent, Complement component 1 subcomponent r, C1R.
Sterile Filtered solution.
Greater than 90.0% as determined by SDS-PAGE.
Description
Human Complement C1r produced in Human plasma having a molecular mass of 92 kDa.
Product Specs
The complement component C1r is initially present in its inactive form, called the C1r proenzyme. Upon activation of the C1 complex, C1r transitions into its active enzymatic state. This activation process is crucial for the initiation of the classical complement pathway. The C1 complex, being the first component in this pathway, is formed through calcium-dependent interactions between one C1q molecule, two C1r molecules, and two C1s molecules. Functionally, C1q is responsible for recognizing and binding to the Fc regions of IgG or IgM antibodies that are bound to antigens, effectively forming immune complexes. This binding event triggers a conformational change within the C1 complex, leading to the activation of C1r. Activated C1r then acts as a protease, cleaving and activating the C1s zymogens within the complex. This cascade of enzymatic reactions results in the generation of active C1s, a serine protease that further propagates the complement cascade by cleaving subsequent complement components. Specifically, the activation of C1r involves its cleavage into two distinct fragments with molecular weights of 57,000 and 35,000 Daltons, signifying its transition from an inactive precursor to an active enzyme.
Human Complement C1r is a protein with a molecular weight of 92 kDa. It is derived from human plasma.
The product is a clear, sterile-filtered liquid.
The product is supplied in a solution containing 1 mg/ml C1r in a buffer composed of 140mM NaCl, 10mM Imidazole, and 8mM EDTA, adjusted to a pH of 7.4.
To ensure product stability, store Human C1r at 4°C for immediate use within 2-4 weeks. For extended storage, it is recommended to freeze the product below -20°C. To further enhance stability during long-term storage, consider adding a carrier protein such as HSA or BSA at a concentration of 0.1%. It's important to avoid repeated freezing and thawing cycles to maintain the integrity of the protein.
The purity of Human C1r is greater than 90%, as determined by SDS-PAGE analysis.
The plasma used in the production process has undergone rigorous testing to ensure the absence of various viral contaminants. Specifically, the plasma has been tested and found negative for antibodies against HIV-1, HIV-2, HCV, HTLV-I/II, syphilis (STS), and hepatitis B surface antigen (HBSAG).
Complement C1r subcomponent, Complement component 1 subcomponent r, C1R.
Human Plasma.
Product Science Overview
Complement C1r is a serine protease enzyme encoded by the C1R gene in humans . It is one of the three subcomponents (C1q, C1r, and C1s) that form the C1 complex, the first component of the classical pathway of the complement system . The C1 complex is responsible for recognizing and binding to antibodies that are attached to pathogens, thereby initiating the complement cascade.
C1r exists as a zymogen, an inactive precursor that requires proteolytic cleavage to become active . Upon activation, C1r cleaves and activates C1s, another serine protease, which then goes on to cleave the complement proteins C4 and C2, leading to the formation of the C3 convertase and the subsequent steps of the complement cascade .
The activation of C1r is a tightly regulated process. It occurs when C1q binds to the Fc region of antibodies (IgG or IgM) that are attached to antigens on the surface of pathogens . This binding induces a conformational change in the C1 complex, leading to the autoactivation of C1r. Activated C1r then cleaves and activates C1s, propagating the complement activation cascade .
Mutations in the C1R gene can lead to deficiencies in C1r, which are associated with various autoimmune diseases, such as systemic lupus erythematosus (SLE) . C1r deficiency can result in impaired clearance of immune complexes and apoptotic cells, leading to increased susceptibility to infections and the development of autoimmune conditions .
Complement C1r is a subject of extensive research due to its critical role in the immune system. It is also a target for therapeutic interventions aimed at modulating the complement system in various diseases. For instance, inhibitors of C1r are being explored as potential treatments for conditions involving excessive complement activation, such as certain autoimmune diseases and inflammatory disorders .
