3h xanthine

[³H]Adenine (25.0 Ci/mmol), [³H]hypoxanthine (27.0 Ci/mmol), [³H]thymidine (20.0 Ci/mmol), [³H]uridine (14.7 Ci/mmol), [³H]uracil (42.8 Ci/mmol), [³H]xanthine (12.8 Ci/mmol) and [³H]adenosine (39.2 Ci/mmol) were obtained from Moravek Biochemicals (Brea, CA), [¹⁴C]guanine (55 mCi/mmol) was from American Radiolabeled Chemicals (St. Louis, MO), and [¹⁴C]ascorbate (8.5 mCi/mmol) was from PerkinElmer Life Sciences (Boston, MA). Adenine, papaverine, and dipyridamole were obtained from Sigma-Aldrich (St. Louis, MO), and hypoxanthine, guanine and nitrobenzylthioinosine were from Wako Pure Chemicals (Osaka, Japan). All other reagents were of analytical grade and commercially obtained.

Kinetic analysis-[³H]-xanthine (21.6 Ci/mmol, Moravek Biochemicals, CA, United States) uptake in MM was assayed in germinating conidiospores of A. nidulans concentrated at 10⁷ conidiospores/100 μL, at 37°C, pH 6.8, as previously described (Krypotou and Diallinas, 2014 (link)). Initial velocities were measured at 1 min of incubation with concentrations of 0.2–2.0 μM of [³H]-xanthine at the polarity maintenance stage (3–4 h, 130 rpm).