SNCA and Parkinson disease: Interestingly, upon performing sequential protein fractionation we found that alpha-synuclein levels were relatively constant in the soluble and Triton-X-100 detergent fractions, however there was an increase in alpha-synuclein, specifically high molecular weight alpha-synuclein in the insoluble fraction of all three PD brain regions, and the cortex of DLB patients (data not shown), with the most pronounced changes found, not surprisingly in the substantia nigra.