[Characteristics of the proteins of tooth enamel].

Three groups of proteins, distinguished by solubility in acidic and neutral media, were found in enamel. Molecular weight of the major part of proteins, insoluble at neutral pH, was about 20000; these proteins readily interacted with Ca2+, developing tri- and tetrameric molecules. High molecular enamel protein reversibly disaggregated after removing of Ca2+ by various methods. The insoluble protein had a highly regular structure. Mineralization of the protein appears to occur due to development of bonds between Ca2 and some amino acid residues.