Fig. 4: PAPP-A2 and PAPP-A feature differences in the mechanism of IGFBP5 cleavage.

a Comparison of FL IGFBP5 binding to the catalytically inactive version of PAPP-A2 (E500Q) and PAPP-A (E483A) using a fluorescent polarization assay. Fluorescently labeled FL IGFBP5 was used as the substrate and catalytically inactive PAPP-A2 and PAPP-A proteins were used to prevent substrate cleavage. b Comparison of PAPP-A2 and PAPP-A IGFBP5 cleavage using equimolar enzyme concentrations. Representative data is shown in Supplementary Fig. 11. c Schematic diagram of PAPP-A2 truncation proteins and cleavage assay comparison with wild type PAPP-A2. Protein quality is shown in Supplementary Fig. 12a and representative data in Supplementary Fig. 12b. d Schematic diagram of PAPP-A monomer variants with M2 domain PAPP-A2 insertions and cleavage assay comparison with FL PAPP-A2 and PAPP-A. Protein quality is shown in Supplementary Fig. 15a and representative data in Supplementary Fig. 15b. For all experiments in this figure error bars represent the standard deviation of experiments done in triplicate.