Fig. 4. Presence of cleaved human TTR in transgenic human ATTR amyloid.

Homogenates of heart, tongue and liver from amyloidotic line O5 and line N4 mice (a and b, respectively) were fractionated into soluble and insoluble fractions, and analysed by western blotting. Lanes labelled H contain unfractionated homogenates, lanes labelled S1 contained the soluble fraction (first supernatant), and lanes labelled P contained the insoluble fraction (pellet). The line O5 mouse (a) was homozygous wild-type for mouse ttr and the line N4 mouse (b) was homozygous for the mouse ttr knockout allele. The same proportion of the entire sample was loaded in each lane; two exposures are shown in a to reveal all relevant bands. Data are representative of n = 5 (a) and n = 2 (b) biological replicates. Lanes labelled R contained recombinant human TTR^S52P that had undergone limited tryptic cleavage; the positions of full-length TTR protomer, the 49–127 cleavage product and mouse TTR are indicated. Glycosylated human TTR protomer is indicated by asterisks. Source data are provided as a Source Data file.