Native human C8 is a glycosylated protein consist of 3 polypeptide chains: The alpha chain and the gamma chain are disulfide linkedwhereas, The beta chain is non-covalently bound to the a-g complex. C8 is necessary for formation of the membrane attack complex and is activated by binding on the cell membrane newly-formed C5b,C6,C7 complexes. Each pathway of complement activation generates proteolytic enzyme complexes which bind the target surface. These enzymes cleave a peptide bond in the larger alpha chain of C5 releasing C5a and activating C5b. Although C5b is unstable it remains bound to the activating complex for a few minutes during which it binds a single C6 from the surrounding fluid or it decays and is no longer capable of forming MAC.The C5b,6 complex may also remain connected to the C3/C5 convertase where the binding of a single C7 exposes a membrane-binding region and C5b,6,7 can enter into the bilipid layer of the target cell. Each C5b-7 complex can bind 1 molecule of C8 causing the complex to enter more firmly into the membrane.
Human Complement C8 produced in Human plasma is glycosylated polypeptide chain conteining 3 chains and having a total molecular mass of 151kDa.
Sterile filtered solution.
C8 protein solution contains 10mM Sodium phosphate and 145mM NaCl, pH 7.3.
C8 Human is stable at 4°C if entire vial will be used within 2-4 weeks.
Store, frozen below -20°C for longer periods of time.
For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA).
Avoid multiple freeze-thaw cycles.
Greater than 90.0% as determined by SDS-PAGE.
Human Virus Test
Plasma from each donor has been tested and found negative for antibody to HIV-1, HIV-2, HCV and HBSAG.