▁processes . ▁This ▁protein ▁is ▁composed ▁of ▁alpha ▁and ▁beta ▁pol ype pt ide ▁ch ains ▁that ▁are ▁linked ▁by ▁a ▁dis ulf ide ▁bridge . ▁An ▁activation ▁pe pt ide , ▁C 5 a , ▁which ▁is ▁an ▁an aph yl ato x in ▁that ▁poss esses ▁pot ent ▁sp asm ogen ic ▁and ▁chem ot actic ▁activity , ▁is ▁derived ▁from ▁the ▁alpha ▁pol ype pt ide ▁via ▁cle av age ▁with ▁a ▁C 5 - convert ase . ▁The ▁C 5 b ▁mac rom ole cular ▁cle av age ▁product ▁can ▁form ▁a ▁complex ▁with ▁the ▁C 6 ▁complement ▁component , ▁and ▁this ▁complex ▁is ▁the ▁basis ▁for ▁formation ▁of ▁the ▁memb rane ▁attack ▁complex , ▁which ▁includes ▁additional ▁complement ▁components . ▁ ▁C lin ical ▁significance ▁▁ ▁Mut ations ▁in ▁this ▁gene ▁cause ▁complement ▁component ▁ 5 ▁def ic iency , ▁a ▁disease ▁where ▁patients ▁show ▁a ▁prop ens ity ▁for ▁severe ▁rec urrent ▁in fe ctions . ▁De fect s ▁in ▁this ▁gene ▁have ▁also ▁been ▁linked ▁to ▁a ▁sus cept ibility ▁to ▁li ver ▁fib ros is ▁and ▁to ▁r he um ato id ▁ar th rit is . ▁ ▁Th era pe ut ic ▁applications ▁▁ ▁The ▁drug ▁e cul iz um ab ▁( tra de ▁name ▁Sol ir is ) ▁prevents ▁cle av age ▁of ▁C 5 ▁into ▁C 5 a ▁and ▁C 5 b . ▁ ▁Com plement ▁system ▁path way ▁ ▁References ▁ ▁Further ▁reading ▁ ▁External ▁links ▁▁▁ ▁Category : Com plement