Table I.

Inhibition of in vitro SAH hydrolase activity by adenosine

Ado Concentration at Start of the AssaySAH Hydrolase ActivityInhibition
μm nmol min−1mL−1 %
05.9
0.54.425.4
1.02.950.9
5.01.869.5
251.574.1
1001.377.9

SAH hydrolase activity (SAH → Ado and Hcy) was measured using crude desalted extracts of Arabidopsis leaves in the presence and absence of added Ado. The starting concentration of SAH in each assay was 150 μm. A representative set of assay results are shown.