Figure 10.

(A) Schematic representation of selected tau fragments with the number of PrSMs that unambiguously identify 0/1N or 3/4R tau. 0N and 1N fragments are being shown as sharing the same KKVAV residues at their C-terminus, while 3R and 4R proteoforms share VRTPP at their N-terminus. Residues underlined are the KVAVVR hexapeptide sequence in the second proline-rich region of tau which is cleaved at proteolytic cleavage site #1. The 3R and 4R hexapeptide motifs are not shown but are both cleaved at proteolytic cleavage site #2. (B) Sequence coverage map of MAPT 1N3R (Tau-B) showing all proteoforms that could be mapped to this isoform with a unique amino acid start and end site. Red lines at the bottom represent the positions of proteolytic cleavage sites #1 and #2. Color scale represents the number of observed PrSMs that can be mapped to the corresponding segment. Unknown mass shifts were not utilized in this analysis.