3.4.24.B6 proteolytic cleavage of ameloblastin MMP-20 is secreted along with enamel proteins by secretory stage ameloblasts into the enamel matrix of developing teeth. Enamel protein cleavage products accumulate in the space between the crystal ribbons, helping to support them. MMP-20 steadily cleaves accumulated enamel proteins, so their concentration decreases with depth. The principle functions of MMP-20 in dental enamel formation is to facilitate the orderly replacement of organic matrix with mineral, generating an enamel layer that is harder, less porous, and unstained by retained enamel proteins 691154 3.4.24.B6 proteolytic degradation of ameloblastin - - 3.4.24.B6 proteolytic degradation of ameloblastin active site with the consensus sequence HEXGHXXGXXH at positions 226-236 649826 3.4.24.B6 proteolytic degradation of ameloblastin mechanism and active site structure analysis, binding pockets and substrate specificity 652736