Characterizing antibody specificity to different protein morphologies by AFM.
Protein misfolding and aggregation can lead to several neurodegenerative diseases including Alzheimer's Disease (AD), Parkinson's Disease (PD) and Huntington's Disease (HD). While the respective proteins involved in each disease differ in their pathological effects and amino acid sequences, the aggregated forms all share a common cross beta-sheet conformation. Substantial controversy exists over the roles of the different aggregate morphologies in disease onset and progression, and analytical tools such as morphology specific antibodies are needed to distinguish between the different protein morphologies in situ. Here we utilize atomic force microscopy (AFM) to characterize the binding of three single chain antibody fragments (scFvs) to different morphologies of alpha-synuclein (alphaS). From the topographic images generated using the AFM, we were able to show that one scFv bound all morphologies of alphaS, a second bound only oligomeric alphaS, and a third bound only fibrillar alphaS by comparing the height distribution of the different alphaS morphologies with and without addition of the different scFvs. These results demonstrate the versatility of the AFM-based technique as an easy tool to characterize specific antigen-antibody binding and the potential applications of scFvs as promising immunodiagnostics for protein misfolding diseases.
Wang
Min S
MS
Department of Chemical Engineering, Arizona State University, Tempe, Arizona 85287-6006, USA.
Zameer
Andleeb
A
Emadi
Sharareh
S
Sierks
Michael R
MR
D000918:Antibody Specificity; D000936:Antigen-Antibody Complex; D001665:Binding Sites; D007135:Immunoglobulin Variable Region / Q000737:chemistry* / Q000302:isolation & purification; D018625:Microscopy, Atomic Force; D051844:alpha-Synuclein / Q000737:chemistry* / Q000302:isolation & purification
D000936:Antigen-Antibody Complex; D007135:Immunoglobulin Variable Region; D051844:alpha-Synuclein