Trans-active response DNA-binding protein (TDP-43) is a multifunctional regulatory protein, whose abnormal deposition in neurons was linked to debilitating neurodegenerative diseases, such as amyotrophic lateral sclerosis, frontotemporal lobar degeneration, Limbic-predominant age-related TDP-43 encephalopathy, and Alzheimer’s disease with a secondary pathology. Several reports showed that TDP-43 proteinopathy as a comorbidity can form aggregates with other pathological proteins. The co-deposition of alpha synuclein and TDP-43 inclusions was previously reported in glial cells and by observing TDP-43 proteinopathy in Lewy body disease. In this study, it was hypothesized that alpha synuclein and TDP-43 may co-aggregate, resulting in comorbid synucleinopathy and TDP-43 proteinopathy. A solid-phase microplate-based immunoassay was used to map out the epitopes of anti-TDP-43 antibodies and locate the interaction of TDP-43 with α-synuclein. A region of the low complexity domain of TDP-43 (aa 311–314) was shown to interact with full-length α-synuclein. Conversely, full-length TDP-43 was shown to bind to the non-amyloid beta component of α-synuclein. Using in silico sequence-based prediction, the affinity and dissociation constant of full-length TDP-43 and α-synuclein were calculated to be −10.83 kcal/mol and 1.13 × 10
−8, respectively. Taken together, this microplate-based method is convenient, economical, and rapid in locating antibody epitopes as well as interaction sites of two proteins.
View Full-Text
►▼
Show Figures
This is an open access article distributed under the
Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited