Fig. 2

The two site inhibition curves show distinct high and low binding components in plasma from Parkinson’s Disease (PD-blue, squares), Multiple System Atrophy (MSA-green, triangles) patients and normal control (NC-black, circles) subjects. Ten plasma samples from each group were pooled and incubated with increasing concentration of α-synuclein monomer with subsequent measurement of free NAbs by ELISA or Meso Scale Discovery (MSD) assays. a ELISA: 10 μg/mL α-synuclein coating, plasma dilution 1:400; b ELISA: 5 μg/mL α-synuclein coating, plasma dilution 1:200; c MSD assay: 5 ng/mL α-synuclein coating, plasma dilution 1:500. The relative binding of anti-α-synuclein NAbs is expressed as a percentage of maximal binding attained in the assay for each sample, where competition reactions with 1000 nM α-synuclein monomer are defined as constituting non-specific (background) binding and reactions without competition reflect 100% (maximum) binding. The line represents the fitting of a two site model to the data