Figure 3.

Western blots of native and dephosphorylated tau from a PPND brain. Insoluble fractions from gray and white matter were probed with the anti-tau mAb identified above each blot. Dephosphorylation reveals two predominant bands in tau from PPND brain that align with recombinant 4Rtau isoforms with an apparent molecular weight of 52 and 59. Molecular weight standards are shown in the left margin, and the positions of each of the nonphosphorylated recombinant human tau isoforms are labeled. Lane 1 shows PHFtau from AD brain. Lanes 2 and 3 show native and dephosphorylated tau, respectively, from gray matter of a PPND brain. Lanes 4 and 5 show native and dephosphorylated tau, respectively, from white matter of a PPND brain. Lane 6 shows all six recombinant tau isoforms (Rtau). Gi and Gd are native (i.e., insoluble) and dephosphorylated tau, respectively, from gray matter of a PPND brain. Wi and Wd are native and dephosphorylated tau, respectively, from white matter of a PPND brain. 0N3R, 1N3R, and 2N3R are three repeat tau isoforms with no vs. one or two amino terminal inserts, respectively. 0N4R, 1N4R, and 2N4R are four repeat tau isoforms with no vs. one or two amino terminal inserts, respectively.