Dependence of Trichomonas vaginalis upon polyamine backconversion.
Trichomonas vaginalis grown for 16 h in the presence of [(14)C]spermine formed a high intracellular pool of [(14)C]spermidine and a small but detectable pool of [(14)C]putrescine. When [(3)H]putrescine was added to the growth medium, a large intracellular pool of [(3)H]putrescine was found, but it was not further metabolized, confirming previous studies suggesting the absence of a forward-directed polyamine synthetic pathway in T. vaginalis. Spermidine:spermineN:(1)-acetyltransferase (SSAT) and polyamine oxidase enzyme activities were detected which collectively converted spermine to spermidine. Polyamine oxidase was localized in the hydrogenosome-enriched fraction, whereas SSAT was found predominantly in the cytosolic fraction. In the presence of saturating substrate, the trichomonad SSAT had an activity of 0. 39+/-0.09 nmol min(-1) (mg protein)(-1) (the mean of five analyses) and an apparent K:(m) for spermine of 1.7 microM. The enzyme was competitively inhibited by di(ethyl)norspermine with a K:(i) of 28 microM. Growth studies indicated that 50 microM di(ethyl)norspermine caused a 68% and 84% reduction in the intracellular concentrations of spermidine and spermine, respectively. The trichomonad polyamine oxidase required FAD as a cofactor and had an apparent K:(m) of 6.0 microM for N(1)-acetylspermine. The potential of bis(alkyl) polyamine analogues as antitrichomonad agents is discussed.
Yarlett
Nigel
N
Haskins Laboratories1 and Department of Chemistry and Physical Sciences2, Pace University, 41 Park Row, New York, NY 10038, USA.
Martinez
Martha P
MP
Haskins Laboratories1 and Department of Chemistry and Physical Sciences2, Pace University, 41 Park Row, New York, NY 10038, USA.
Goldberg
Burt
B
Department of Biology, St Francis College, 180 Remsen Street, Brooklyn, NY 11201, USA3.|Haskins Laboratories1 and Department of Chemistry and Physical Sciences2, Pace University, 41 Park Row, New York, NY 10038, USA.
Kramer
Debora L
DL
Grace Cancer Drug Center, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA4.
Porter
Carl W
CW
Grace Cancer Drug Center, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA4.
D000123:Acetyltransferases / Q000378:metabolism; D000818:Animals; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000378:metabolism; D011700:Putrescine / Q000378:metabolism*; D013096:Spermine / Q000378:metabolism*; D013347:Subcellular Fractions / Q000201:enzymology; D014246:Trichomonas vaginalis / Q000254:growth & development / Q000378:metabolism*; D000097667:Polyamine Oxidase; D000099228:Diamine N-Acetyltransferase
D000123:Acetyltransferases; D000587:Oxidoreductases Acting on CH-NH Group Donors; D011700:Putrescine; D013096:Spermine; D000097667:Polyamine Oxidase; D000099228:Diamine N-Acetyltransferase