Complement factor I, C3B/C4B inactivator, CFI, IF.
CFI cleaves and inactivates C3b and C4b. CFI is inactive without a cofactor such as the soluble factor H and C4b binding protein. CFI cleaves the alpha-peptide chain of C3b and C4b when these binds1 of the cofactors. This cleavage inactivates all of the complement activating functions of these proteins producing iC3b and iC4b.CFI cleaves the alpha chain of C3b twice and this releases a small fragment called C3f. CFI can cleave iC3b releasing C3c from C3dg in the presence of CR1.C4b is cleaved rapidly at 2 sites separating C4c from C4d.
Human Complement Factor I produced in Human plasma is glycosylated polypeptide composed of 2 disulfide-linked chains having a total molecular mass of 88kDa.
Sterile filtered solution.
CFI protein solution contains 10mM Sodium phosphate and 145mM NaCl, pH 7.2.
CFI 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 95.0% 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.