[¹²⁵I]SIL23 exhibits specific binding to insoluble protein from human PD brain samples but not control human brain samples.

<p>Homogenized insoluble fractions from human brain samples (n = 8) were incubated with increasing concentrations of [¹²⁵I]SIL23. Nonspecific binding was determined in parallel reactions utilizing 50 µM ThioT as competitor. Representative plots of specific binding versus [¹²⁵I]SIL23 concentration are shown. <b>A–D</b> show four different PD cases and <b>E–H</b> show four control cases. The data was analyzed by curve fitting to a one-site binding model using nonlinear regression. K_d values for binding to PD-dementia brain samples range from 119.1 nM to 168.3 nM and B_max values range from 13–25 pmol/mg insoluble protein. No significant binding of [¹²⁵I]SIL23 to control samples was observed. Results were verified with at least two independent experiments.