Fig. 5

Immunochemical characterization and storage study. a: Dose-response curves for 4 IA-2A RBA positive Type 1 diabetic patient sera incubated with different concentrations of TrxIA-2_ic. Each curve includes best-fit values from the log (inhibitor) vs. response - Variable slope (four parameters) equation: correlation coefficient data (R²), IC₅₀ values and an approximation to the affinity constant of IA-2A (K_a) calculated as the inverse of IC₅₀. b: Inhibition capacity of TrxIA-2_ic assessed in 30 IA-2A positive type 1 diabetic patient sera in the absence (left) or presence (right) of TrxIA-2_ic. Twenty healthy control sera were used in order to set a cut-off value. c: Dose-response curves for a pool of 3 IA-2A RBA positive Type 1 diabetic patient sera for different concentrations of TrxIA-2_ic (open circle, solid line) and TrxIA-2_ic-biotin (closed circle, dotted line). d: Inhibition capacity of TrxIA-2_ic-biotin assessed in 30 IA-2A positive Type 1 diabetic patient sera in the absence (left) or presence (right) of TrxIA-2_ic-biotin. Twenty healthy control sera were used in order to set a cut-off value. Binding is expressed as SDs, and the dotted lines represent the cut-off value. e: IC₅₀ vs. storage time for TrxIA-2_ic stored at -20 °C in 100 mM 2ME lysis buffer (solid line) and -20 °C in 50 % glycerol, 50 mM 2ME lysis buffer (dotted line). These assays were performed by standard RIA protocols, as described in Methods.