Fig. 2.
Characterization of [3H]-uracil transport in T. b. brucei bloodstream forms. (A) Inhibition of 0.15 μM [3H]-uracil uptake over 30 seconds by various concentrations of unlabeled uracil. Inset: conversion to Michaelis-Menten saturation plot. (B) Dose-dependent inhibition of 0.15 μM [3H]-uracil transport by uridine (■), 5-fluorouracil (●), and 5-bromouracil (□). Incubations (30 seconds) were terminated by the addition of 1 ml ice-cold 1 mM uracil in assay buffer and immediate centrifugation through oil. Error bars are S.E.M. of triplicate determinations.