Table IV.

Enzymatic assays of AtAPM1 and AtAPP1 produced by in vitro translation

Substrate/InhibitorAtAPM1AtAPP1
nmol min−1 mg−1
Tyr-AFC59 ± 5.836 ± 4.9
Tyr-AFC + kaempferol32 ± 3.1 30 ± 5.5
Tyr-AFC +PAQ2217 ± 5.4 47 ± 3.1
Tyr-AFC + apstatin54 ± 6.915 ± 4.7
Tyr-AFC +EGTA16 ± 6.4 19 ± 2.2
Ala-Pro-AFC6 ± 4.274 ± 3.1
Ala-AFC35 ± 4.25 ± 4.8
Pro-AFC18 ± 5.329 ± 6.1
Trp-AFC4 ± 3.220 ± 1.7
Leu-AFC5 ± 3.17 ± 1.9
NPA8 ± 3.43 ± 1.4

AP and amidase assays with substrates and inhibitors indicated. Inhibitor concentrations used were as in Table II. Units are nmol AFC or β-NA released min−1 mg−1. Values reported are means and sd of three independent experiments. Student-Newman-Keuls ANOVA indicates that the Tyr-AFC-related values reported are different from a normal distribution (P < 0.001). Values marked with an asterisk differ from controls in pair-wise comparisons (P < 0.05).