Evidence that eosinophils catalyze the bromide-dependent decarboxilation of amino acids.

Human eosinophils from subjects with or without myeloperoxidase (MPO) deficiency and guinea pig eosinophils are able to decarboxylate 1-alanine in the presence of the cationic detergent cetyltrimethylammonium bromide (CTAB) but not in the presence of the nonionic detergent Triton X-100. Instead both normal human neutrophils and guinea pig neutrophils decarboxylate 1-alanine in the presence of either detergent. When the non-bromidecontaining cationic detergent cetyltrimethylammonium hydroxide (CTAOH) is used instead of dAB. the eosinophils from MPO-deficient subjects are unable to decarboxylate L-alanine. Decarboxylation occurs with the combination CTAOH-Br, but not with the combinations CTAOHI. CTAOH-Cr. or CTAOH-F . Bromide in the absence of CTAOH does not promote decarboxylation. Triton X-100 and deoxycholate are much less effective in promoting decarboxylation in the presence of bromide. L-Lysine and 1-aspartic acid are decarboxylated to a considerably lower rate than L-alanine in the presence of CTAOH and Br . It is concluded that the eosinophils can catalyze the bromidedependent decarboxylation of the apolar amino acid L-alanine in the presence of a cationic detergent.