Fig. 1: Biochemical characterization of the p-tau212- and p-tau217-specific sheep mAbs.

Each panel shows the results of direct ELISAs where the p-tau212 and p-tau217 antibodies were each titrated against fixed concentrations of the indicated synthetic peptide or recombinant protein. The numbers at the start and the end of the horizontal schematics refer to the amino acids at the beginning and the end of the synthetic peptides. Colored circles represent phosphorylated site on the peptide. Checked circles represent epitopes proven to be phosphorylated by a dual specificity tyrosine phosphorylation regulated kinase 1A (DYRK1A) kinase. a Binding profiles of the p-tau212 and p-tau217 antibodies to a synthetic peptide (Bt-x-SRpTPSLPTPPTREPK, where Bt-x refers to biotinylation) that was phosphorylated specifically and exclusively at threonine-212. b Kinetic profiles of the p-tau212 and p-tau217 antibodies to a synthetic peptide that had the same sequence as in (a) above but was rather phosphorylated only at threonine-217 (Bt-x-SRTPSLPpTPPTREPK). c Binding characteristics of the p-tau212 and p-tau217 antibodies to the same sequence of synthetic peptide as in (a) and (b) but was phosphorylated at both the threonine-212 and threonine-217 sites (Bt-x-SRpTPSLPpTPPTREPK). d Binding profiles of the p-tau212 and p-tau217 antibodies to the same peptide sequence as in (a–c) except that it was phosphorylated jointly at threonine-212, serine-214 and threonine-217 (Bt-x-SRpTPpSLPpTPPTREPK). e Binding characteristics of the p-tau212 or p-tau217 antibodies to a recombinant form of full-length tau 441 (2N4R) that was phosphorylated in vitro by DYRK1A kinase. This kinase phosphorylates tau at multiple other sites beyond threonine-212 and threonine-217 but not at serine-214²⁹. f Binding profiles of the p-tau212 or p-tau217 antibodies to a recombinant full-length tau 441 (2N4R) that was not phosphorylated at any site. g Binding characteristics of antibodies to peptide (bt-x-SRTPpSLPTPPTREPKK) specifically phosphorylated at serine-214. h Binding profile of antibodies to a peptide (bt-x-KKVAVVRpT(HOMOPRO)PKSPSSAK) specifically phosphorylated at threonine-231. P-tau231 specific antibody was used as a positive control. i Binding profile of antibodies to a peptide (bt-x-APKpTPPSSGE) specifically phosphorylated at threonine-181. P-tau181 specific antibody was used as a positive control. Source data are provided as a Source Data file.