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. Author manuscript; available in PMC: 2019 May 1.
Published in final edited form as: J Autoimmun. 2018 Jan 4;89:171–185. doi: 10.1016/j.jaut.2017.12.017

Figure 7. Identification of key amino acid residues for FS IgG4 binding.

Figure 7

(A)The locations of the mutated residues (blue, lime green, yellow and dark purple) in the EC1 epitope (red) are shown on the homology model of the Dsg1/Dsc1 heterodimer (light (Dsg1) and dark (Dsc1) gray). (B) Affinity-purified FS1 IgG4 antibodies on the llama anti-human IgG4 and Dsg1-EC1/Dsg3 bb columns were tested against wDsg1 (blue), Dsg1-m1 (red), Dsg1-m2 (green) and wDsg3 (purple) by ELISA. A stock of IgG4 (0.3 mg/ml) from each patient at a dilution of 1:5,000 was tested on microtiter wells coated with different amounts of the recombinant protein (from 12.5 ng/well to 50 ng/well). Peroxidase-labeled mouse anti-human IgG4 at a dilution of 1:2,000 was used as an indicator. The results are expressed in OD490nm units. (C) Affinity-purified FS1 IgG4 antibodies on the llama anti-human IgG4 and Dsg1-EC1/Dsg4 bb columns were tested against wDsg1 (blue), Dsg1-m1 (red), Dsg1-m3 (green) and wDsg4 (purple) by ELISA. A stock of IgG4 (0.3 mg/ml) from each patient at a dilution of 1:5,000 was tested on microtiter wells coated with different amounts of the recombinant protein (from 12.5 ng/well to 50 ng/well). Peroxidase-labeled mouse anti-human IgG4 at a dilution of 1:2,000 was used as an indicator. The results are expressed in OD490nm units.