Enzymes of Trichomonas foetus. The action of cell-free extracts on blood-group substances and low-molecular-weight glycosides

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Abstract
Cell-free extracts of Trichomonas foetus contain enzymes which destroy the serological properties of human water-soluble A-/B-, H- and Lea-blood-group substances. The optimum for each enzyme is between pH 6 and 7. Dialysis of the T. foetus extracts against distilled water results in loss of enzyme activity on the Wood-group substrates, but inactivation is reversed by the addition of salts. The enzymes acting on A-, B-and H-substances are stable to heating for 30 minutes at 55[degree] but considerable inactivation of the Lea enzyme occurs under these conditions. Incubation of A-, B-, H- and Lea-substances for 18 hours at 37[degree] with the T foetus extract results in the production of about 20% of reducing sugars and a liberation of fucose, galactose and N-acetylhexosamine. In addition to its action on the blood-group substrates the T foetus preparation hydrolyzes compounds of known structure containing [alpha] -or [beta]-galactoside, [alpha]- or [beta]-glucoside, N-acetyl-[alpha] - or [beta]-glucosaminide, N-acetyl-[alpha]- or [beta]-galactosaminide, [alpha]-L-fucoside or [alpha]-L-rhamnoside linkages. The possible relationships between the enzymes acting on the low-molecular-weight substrates and those acting on the blood-group substrates are discussed.