Anatomy and Cell Biology Publications
Title
Detection of Amyloid Beta (A beta) Oligomeric Composition Using Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (MALDI MS)
Document Type
Article
Publication Date
4-2018
Issue
4
Journal
Journal of the American Society for Mass Spectrometry
Volume
29
First Page
786
Last Page
795
URL with Digital Object Identifier
https://doi.org/10.1007/s13361-018-1896-z
Abstract
The use of MALDI MS as a fast and direct method to detect the A beta oligomers of different masses is examined in this paper. Experimental results suggest that A beta oligomers are ionized and detected as singly charged ions, and thus, the resulting mass spectrum directly reports the oligomer size distribution. Validation experiments were performed to verify the MS data against artifacts. Mass spectra collected from modified A beta peptides with different propensities for aggregation were compared. Generally, the relative intensities of multimers were higher from samples where oligomerization was expected to be more favorable, and vice versa. MALDI MS was also able to detect the differences in oligomeric composition before and after the incubation/oligomerization step. Such differences in sample composition were also independently confirmed with an in vitro A beta toxicity study on primary rat cortical neurons. An additional validation was accomplished through removal of oligomers from the sample using molecular weight cutoff filters; the resulting MS data correctly reflected the removal at the expected cutoff points. The results collectively validated the ability of MALDI MS to assess the monomeric/multimeric composition of A beta samples.
