Figure 7.

TLN activity[8] was determined from initial velocity measurements with 10 µM substrate in 50 mM HEPES buffer (pH 7.4) containing 10 mM CaCl₂, 5 mM NaCl and 10 µM ZnCl₂ (final reaction volume 100 µL, final enzyme concentration 5 nM). The fixed time assay involved incubation of substrate with TLN for 30 min and the relative fluorescence units data (RFU) obtained was converted to % TLN activity and plotted against the time aliquots were withdrawn. Conditions include: (●) no inhibitor, 0.5 mM ascorbate; (●) 1 µM [Cu²⁺•Cys-Gly-His-Lys], no ascorbate; (●) 1 µM [Cu²⁺•Cys-Gly-His-Lys], 0.5 mM ascorbate (●) 1 µM Cu²⁺(aq), 0.5 mM ascorbate.