Significance of transglutaminase-catalyzed reactions in growth and development of filarial parasite, Brugia malayi.

A novel form of transglutaminase enzyme [EC 2.3.2. 13] was identified in adult worms of Brugia malayi. The molecular size of this enzyme was 22-kilodaltons as determined by Western blot and immunoprecipitation, using a monoclonal (CUB 7401) or polyclonal antibodies against guinea-pig liver tissue transglutaminase. The enzyme was present in female worms only; adult males contained no detectable levels of the enzyme peptide. Possible involvement of transglutaminase-catalyzed reactions in growth and survival of filarial parasites was studied by using various enzyme-specific pseudosubstrates. Presence of these inhibitors resulted into a significant inhibition of microfilariae production and release by gravid female worms in a dose-dependent manner. These results suggest that transglutaminase-catalyzed reactions are essential for development of in utero growing embryos to mature microfilariae.