INFLUENCE OF AROMATIC-COMPOUNDS ON INTERACTION OF ACTIVATED C4 WITH EAC1

  • 1 January 1977
    • journal article
    • research article
    • Vol. 32  (2) , 251-256
Abstract
The influence of amino acids and their derivatives on the formation of SAC14 [erythrocyte (E) antigenic site, antibody plus the 1st and 4th complement components] from SAC1 and C4 were investigated. Among the compounds tested, aromatic amino acids containing phenolic hydroxyl group or carbobenzoxyl group inhibited the formation of SAC14. When aromatic compounds other than amino acids were tested, the inhibitory capacities of these compounds were related to the substituent group incorporated in the aromatic ring. Aromatic compounds with substituent groups with negative Hammett''s substituent constant showed stronger inhibition. Compounds having groups with positive constants showed weaker inhibition. The increased electron density in the aromatic ring is probably responsible for the inhibition. Regardless of inhibition of SAC14 formation, these inhibitors did not affect the enzymatic action of EAC1 or C1 on C4 but inhibited the binding of activated C4 to EAC1.