TABLE 3

Aglycone formation measured by studies with selected enzymes

Enzymatic Systema
Metaboliteobs
Metabolitenonenzymatic
nmol
Purine Nucleoside Phosphorylase
   Inosine*** 91 ± 3 0.08 ± 0.03
   BDCRB 0.21 ± 0.05 0.19 ± 0.05
   Maribavir <0.006b <0.006b
Thymidine Phosphorylase
   Thymidine*** 104 ± 5 0.24 ± 0.03
   BDCRB 0.16 ± 0.03 0.19 ± 0.05
   Maribavir <0.006b <0.006b
tRNA-Guanine Transglycosylase
   BDCRB 0.15 ± 0.03 0.14 ± 0.03
   Maribavir <0.006b <0.006b
N-Methylpurine DNA Glycosylase
   BDCRB*** 77 ± 4 0.18 ± 0.04
   Maribavir <0.006b <0.006b
8-Oxoguanine DNA Glycosylase
   BDCRB*** 63 ± 5 0.21 ± 0.06
   Maribavir <0.006b <0.006b
   TCRB*** 37 ± 2 0.14 ± 0.03
   FTCRI 0.19 ± 0.04 0.17 ± 0.03
   Adenosine 0.52 ± 0.06 0.49 ± 0.04
   Inosine 0.09 ± 0.04 0.10 ± 0.03
   Guanosine
0.35 ± 0.02
0.39 ± 0.04

  • ↵*** p<0.0001 determined by two-tailed t tests comparing metabolite formed in the presence vs. absence of enzyme

  • ↵ a Each enzyme was diluted to 3 μg/ml in the appropriate reaction buffer, in which 200 μM substrate was also prepared. Reactions were aliquoted into methanol at 0 and 60 min. Aglycone was quantitated by HPLC, and resulting values are reported as mean ± S.D. (n = 3)

  • ↵ b Limit of detection, since no measurable aglycone was detected