Fig. 1.
Sequence of Aβ1–42 and N-terminal truncated Aβ starting at position 3. a Aβ1–42 starts at position 1 with aspartate (D), Aβ3E–42 at position 3 with glutamate (E), and Aβ3Q–42 with glutamine (Q). Both N-truncated Aβ3E–42 and Aβ3Q–42 peptides can be converted into pyroglutamate-Aβ3(pE)–42. b Schematic drawing of the transgenic vector. TBA2 transgenic mice express Aβ3(Q)–42 under the control of the Thy1 promoter fused to the signal peptide of the pre-pro-thyrotropin-releasing hormone. c N-terminal Aβ starting with glutamate (Aβ3E) or glutamine (Aβ3Q) at position 3 serves as substrates for generation of Aβ3(pE). The conversion of pyroglutamate from N-terminal glutamate (E) is slow, in contrast to fast pyroglutamate (pE) formation from glutamine (Q) [12]