A comparative study of the protein content of some helminths and the suitability of assay methods

The protein content of fresh homogenates and their corresponding TCA precipitated fractions of 10 different species of helminths was estimated by the methods of Lowry et al. and Spector using the Folin phenol reagent and Coomassie brilliant blue G-250 respectively. The former method gives exaggerated values as compared to the latter method. The parasite phenols, phenolic proteins and catecholamines could be responsible for interference in the Lowry's procedure. The TCA noln-precipitable moieties also give colour only with the Folin phenol assay. The pronounced intra-specific differences in the total protein content of helminths reflect their metabolic variations and adaptations. Habitat does not appear to influence the protein content of parasites, however, the effect of host variation was evident in the pouched amphistome G. crumenifer. It is concluded that the dye binding method gives more consistent results and it can be conveniently applied to crude tissue homogenates of helminths.