Fig. 5
Intracellular stored Aβ42 is truncated in the N-terminus. Aβ ELISAs of cell lysates from 24 h and from 6 to 12 days following Aβ42 protofibril removal (24 h + 6 days and 24 h + 12 days, respectively) demonstrate that a high proportion of the accumulated Aβ is N-terminally truncated. The concentrations of Aβ1-x (a) and Aβ protofibrils (b) decrease continuously from 24 h (2434.0 ± 272.0 and 946.9 ± 36.5, respectively) to 24 h + 6 days (862.8 ± 92.0 and 325.8 ± 25.9, respectively) and 24 h + 12 days (468.2 ± 52.2 and 282.9 ± 13.1, respectively), while the concentrations of Aβx-42 remain higher over time (24 h: 2475.0 ± 134.0, 24 h + 6 days: 226.01 ± 318.3 and 24 h + 12 days: 1531.0 ± 253.1) (c). In the pellets, remaining after the cell lysis procedure, the Aβ1-x concentrations decline over time (24 h: 1840.0 ± 289.5, 24 h + 6 days: 938.3 ± 159.7, 24 h + 12 days: 483.3 ± 225.3) (d), while the Aβx-42 concentrations are higher at 24 h (2422.0 ± 387.0) and more stable over time, 24 h + 6 days (1493.0 ± 132.7) and 24 h + 12 days (1488.0 ± 312.6) (e). All concentrations are expressed in picomolar (pM) units. Mean values are from duplicates of three independent experiments