Chick embryo anchored alkaline phosphatase and mineralization process in vitro.

摘要: Bone alkaline phosphatase with glycolipid anchor (GPI-bALP) from chick embryo femurs in a medium without exogenous inorganic phosphate, but containing calcium and GPI-bALP substrates, served as vitro model of mineral formation. The mineralization process was initiated by the formation arising hydrolysis substrate GPI-bALP. Several media different substrates were analysed after an incubation time ranging 1.5 h to 144 h. measurements Ca/Pi ratio infrared spectra permitted us follow presence amorphous noncrystalline structures, while analysis X-ray diffraction data allowed obtain stoichiometry crystals. phosphocreatine, glucose 1-phosphate, 6-phosphate, 1,6-bisphosphate produced hydroxyapatite manner similar that β-glycerophosphate. distinct steps observed. Amorphous phosphate present at onset formation, then poorly formed crystalline structures observed, followed crystals 6–12 h time. However, either ATP or ADP, catalysed calcium-containing medium, did not lead any crystals, even 144 h time, when both nucleotides completed. In contrast, AMP led appearance 12 h depends only on ability hydrolyze organic also nature affecting nucleation producing inhibitors mineralization.