Preferential inhibition of xanthine oxidase by 2-amino-6-hydroxy-8-mercaptopurine and 2-amino-6-purine thiol

BMC Biochemistry

Table 2 Bi-substrate simulative experiment.

Inhibitor (μM)	% Activity with xanthine as substrate	% Activity with 6MP as substrate
ALLOPURINOL 0.5 1.0 2.5	95 ± 1.09 68 ± 3.51 30 ± 1.04	83 ± 1.05 48 ± 1.07 16 ± 1.05
APT 0.5 1.0 2.5	96 ± 1.00 90 ± 0.51 80 ± 2.50	73 ± 2.50 66 ± 3.01 25 ± 2.06
AHMP 0.5 1.0 2.5	90 ± 1.09 85 ± 2.06 64 ± 1.02	59 ± 4.01 47 ± 4.01 18 ± 2.08

The reaction mixture comprised of 1 ml of 0.2 M, sodium phosphate buffer pH 7.4 containing 10 μM of both xanthine and 6MP. The concentration range of allopurinol was 0–2.5 μM. The concentration range of AHMP was 0–3 μM. The concentration range of APT was 0–10 μM. The reaction was initiated by the addition of 2.8 U/ml of bovine XOD.

ISSN: 1471-2091