Influence of omega-aminoacids on the activation of the first component of complement at low ionic strength

Cl, is the first component of human complement, was activated to Cls by diluting human plasma in a solution of low ionic strength. The addition of lysine and its related aminoacids to plasma resulted in inhibition of Cl activation, alpha, omega-diaminoacids such as lysine and ornithine were most effective and omega-aminoacids such as 6 aminohexanoic acid were far less effective. Tranexamic acid which is most potent in inhibition of fibrinolysis among those aminoacids was least effective in the inhibition of Cl activation. omega-aminoacids or their analogues hardly inhibited Cls which had already been activated.