Table 2.

Enzyme properties after reduction

Reductant	Experimental condition	Heparin affinity	75Se, cpm/mg protein	Specific activity, μmol/min/mg
				DTNB	Trx + insulin
None	Aerobic	Low	1.1  ×  106	44.8	13.6
NADPH	Aerobic	High	1.1  ×  106	51.0	15.0
TCEP	Aerobic	High	0.6  ×  106	14.6	6.6
TCEP	Anaerobic	High	1.0  ×  106	42.5	12.0
TCEP*	Aerobic	High	0.9  ×  106	42.2	—

NADPH, 5 mM or TCEP, 1 mM was used. 

^*After elution from the heparin column, the sample was supplemented with 1 mM NADPH before buffer transfer and concentration.