Expression of a Highly Antigenic and Native-Like Folded Extracellular Domain of the Human α1 Subunit of Muscle Nicotinic Acetylcholine Receptor, Suitable for Use in Antigen Specific Therapies for Myasthenia Gravis
Figure 3
Binding of antibodies to y-α1-ECD and i-α1-ECD.
A) Anti-nAChR mAbs binding. Partially conformation-dependent anti-MIR mAb (mAb 195), strictly conformation-dependent anti-MIR mAbs (mAbs 192 and 35) and mAb 64 (a conformation-dependent anti-α1, non anti-MIR mAb), were tested in ELISA experiments showing the binding of the anti-nAChR mAbs at increasing volumes to 40 ng of y-α1-ECD or i-α1-ECD. B) Binding of anti-α1 autoantibodies from MG sera. Five anti-nAChR sera were assayed by RIA for binding to 40 ng of purified y-α1-ECD or i-α1-ECD, labeled with 50,000 cpm 125I-α-BTX. Sera 1, 2 and 3 have low titers and sera 4 and 5 are of high titer for anti-nAChR autoantibodies. Bound radioactivity to the immunoprecipitates (Y-axis) was expressed as the % ratio to the bound radioactivity when y-α1-ECD or i-α1-ECD filter assayed with 50,000 cpm 125I-α-BTX. The values are the mean and standard deviation (±S.D.) from 5 experiments. *Statistically significant differences (unpaired t-test, p<0.05). **Statistically very significant differences (unpaired t-test, p<0.01).