Studies on the Adsorption of Complement

Lead phosphate and titanium dioxide remove the mid-piece of complement. Kaolin and Mg(OH)2 are less specific in their action and adsorb both mid-piece and end-piece. Small amounts of aluminum hydroxide gel remove the mid-piece of complement while larger amounts remove the total complement-complex. The action of zymin on serum-complement is of a different nature, inasmuch as zymin in optimal amounts specifically removes the heat-stabile fraction of the mid-piece. Zymin has no adsorptive effect in the presence of 10 per cent NaCl. Chemical analyses of the serum before and after treatment with adsorbents reveal marked variations in the amounts of calcium and protein removed; however a correlation appears to exist between the amount of euglobulin-phosphorus (cephalin) and the adsorption of the mid-piece of complement. It is suggested that the mid-piece of complement is closely associated with a phosphatide in the euglobulin-fraction. An improved method for the separation of complement into its heat-labile components (mid-piece and end-piece) is given.