No inhibition of TrxR1 activity in vitro by addition of SecTRAPs

The values are mean±S.D. of six different measurementsa,The TrxR1 preparation in this experiments was full-length rat TrxR1 and the SecTRAP preparation rat truncated TrxR1.b,TrxR1 activity is given as turnover (min−1) calculated from the decrease at 340 nm detected in a microplate reader assay with 5 nM TrxR1, 0.5 nM-500 nM truncated TrxR1 as SecTRAP, 10 µM Trx, 145 µM Insulin in 50 mM Tris-Cl, 2 mM EDTA, pH 7.4 and 200 µM NADPH.c,TrxR1 activity calculated from the increase at 412 nm detected in a microplate reader assay with 5 nM TrxR1, 2.5 mM DTNB in 50 mM Tris-Cl, 2 mM EDTA, pH 7.4 and 200 µM NADPH based upon comparisons to standard curves performed in normal quartz cuvettes with 1 cm light path length.d,TrxR1 activity in insulin assay with 1∶10 molar ratio of Trx1 (1 µM) and truncated TrxR1 as SecTRAP (10 µM). The turnover (min−1) is calculated from the decrease at 340 nm detected in a microplate reader assay using 5 nM TrxR1, 145 µM insulin in 50 mM Tris-Cl, 2 mM EDTA, pH 7.4 and 200 µM NADPH.n.d.: not determined