Collagen-DPP interactions increase the stability of DPP and induce collagen fibril assembly.
A, SDS-PAGE stained with CBB or CBB plus Stains-all. DPP does not stain with CBB but can be visualized with Stains-all. DPP is not stable when incubated below pH 6 at higher temperature. B, SDS-PAGE showing type I collagen (Col I). Col I stains with CBB but does not stain with Stains-all (SA). C, SDS-PAGE of Col I and DPP after being mixed together and incubated at 4, 20, 37, or 95 °C. The presence of collagen reduces the instability of DPP at 37 and 95 °C.