PROPO SYSTEM OF ALLOGAMUS-AURICOLLIS (INSECTA) - EFFECTS OF VARIOUS COMPOUNDS ON PHENOLOXIDASE ACTIVITY

The phenoloxidase activity in the hemolymph cell-free fraction from Al logamus auricollis was studied in the presence of Escherichia coli lip opolysaccharides and Saccharomyces cerevisiae beta-1,3-glucans. The pr oPO system seems to be strongly activated by lipopolysaccharides (LPS) . The basic activation observed in this model appears not to be affect ed by the use of protease inhibitors (cut macroglobulin, soybean tryps in inhibitor), and, in addition, the LPS-activated proPO system is not inhibited by their presence. Calcium ions at high concentrations inhi bit the phenoloxidase activity, and EDTA chelation strongly enhances d opachrome formation. Analytical polyacrylamide gel electrophoresis (PA GE) of the hemolymph cell-free fraction showed two main components, wi th a molecular mass of 76 and 80 kDa. After electro-elution from a nat ive PAGE of L-dihydroxy-phenylalanine positive bands, the analytical S DS-PAGE again showed the same two major bands.