An oral protist Trichomonas tenax ATCC 30207 was investigated for the ability to lyse erythrocytes of sheep, rabbits, horses and humans. Five fractions, including intact cells, culture supernatant, culture filtrate, cell debris and lipid-enriched fractions, were prepared from the protozoan cells, and their hemolytic activities were assayed under various conditions. All the samples except culture supernatant had hemolytic activities, which were due to two different kinds of hemolysins. One hemolysin was protein-like and mainly found in cell-free fractions: culture supernatant and culture filtrate. It was heat-labile and inhibited by various cysteine-proteinase inhibitors. The other hemolysin was lipid-like and found in cell-associated fractions: intact cells, cell-debris and lipid-enriched fractions. It was heat-stable, organic solvent-tolerant and unaffected by various proteinase inhibitors and stimulators. These results suggested that T. tenax ATCC 30207 possessed two distinct hemolysins, protein and lipid.

An oral parasite Trichomonas tenax ATCC 30207 synthesizes and secretes various proteinases. By gelatin-SDS-PAGE, we found five proteinases bands (30, 37, 46, 51 and 60 kDa) in cell lysate and four bands (37, 45, 52 and 60 kDa) in culture filtrate. The proteinases hydrolyzed acid soluble type I collagen as well as gelatin. The enzymes were suggested to possess typical characteristics of cysteine proteinases based on the patterns of inhibition and activation by various factors. Based on relative efficiencies of synthetic substrates, most of them were most likely cathepsin B-like enzymes.