DSPP is a multi-domain protein that is cleaved by proteases, especially Mmp-2, Mmp-20, and BMP1 into separate proteins. The order of the major DSPP cleavage products in the parent protein is DSP-DGP-DPP, where DSP is dentin sialoprotein, DGP is dentin glycoprotein, and DPP is dentin phosphoprotein. These DSPP-derived proteins serve different functions. DSPP-derived proteins are notable for their extensive post-translational modifications. DSP is a highly glycosylated proteoglycan. DSP, DGP, and DPP are all phosphorylated. DPP is so highly phosphorylated it has the lowest isoelectric point (pH 1) of all proteins. DPP is also polymorphic in it size due to allelic variations in the length of the DPP coding region. Understanding DSPP's structure and function should yield important insights into how dentin biomineralization is controlled.