ANTIOXIDANT ENZYMES IN CRYPTOSPORIDIUM-PARVUM OOCYSTS

Oocysts of Cryptosporidium parvum showed relatively low levels of SOD activity. The SOD which had a pI of 4 . 8 and an approximate molecular weight of 35 kDa appeared to be iron dependent. Catalase, glutathione transferase, glutathione reductase and glutathione peroxidase activit y could not be detected, nor could trypanothione reductase. No NADH or NADPH oxidase activity could be detected, nor could peroxidase activi ty be demonstrated using o-dianisidine, guaiacol, NADPH or NADH as co- substrates. However, an NADPH-dependent H2O2 scavenging system was det ected in the insoluble fraction.