Mode of interaction of different polyanions with the first (), the second (C2) and the fourth (C4) component of complement—II

Abstract Dextran sulfate, polyvinyl sulfate, liquoid, heparin and Sp 54, ∗ (a pentosanpoly-sulfoester) prevented the uptake of C2 by EAC4b. In contrast to EAC 4 b 2 a , treatment of EAC4b2 with polyanions led to dissociation into EAC4b and C2. The inhibition of C2 uptake by polyanions could be reduced by increasing magnesium concentration to levels which are normally inhibitory, suggesting that Mg ++ ions are sequestered by these sulfated polyanions.