Norelle Wildburger, PhD Post-doctoral fellow (2015-)
Norelle is focused on the analysis of Alzheimer’s disease proteins by mass spectrometry. Her goal is to identify proteins primarily responsible for toxicity throughout the disease course, which can be targeted with novel therapeutics.
(A) Liquid chromatography-tandem mass spectrometry (LC-MS/MS) spectrum for undigested, full-length Aβ1-40. Each peak represents an ion fragmented from Aβ1-40, with peaks labeled ‘b’ representing N-terminal fragment ions and peaks labeled ‘y’ representing C-terminal fragment ions. The numbers indicate measured mass/charge ratio (m/z). The single letter amino acid code across the top indicates the de novo sequence identified by mass spectrometry, which matches the amyloid precursor protein sequence corresponding to Aβ1-40. The line breaks between amino acids indicate a cleavage of the amide bond between two adjacent amino acids producing fragment ions. The lines below each amino acid indicate a detected ‘b’ ion, and lines above indicate a detected ‘y’ ion. Inset: isotopic envelope for the +5 charged, full-length Aβ1-40: the peaks are spaced 0.2 daltons apart at z = +5 because the naturally occurring isotopes (e.g. 13C and 15N) differ by 1 dalton. For the +5 ion, the observed m/z was 866.4351 (theoretical m/z = 866.4370), which was −2.1 parts per million (ppm) error from the theoretical mass of Aβ1-40. (B) Spectrum for full length Aβ1-42. For the +5 ion, the observed m/z was 903.2623 (theoretical m/z = 903.2612), which was 1.2 ppm error from the theoretical mass of Aβ1-42.