Ultrastructural and biochemical aspects of matrix vesicle-mediated mineralization.
Ultrastructural and biochemical aspects of matrix vesicle-mediated mineralization.
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DOI：
10.1016/j.jdsr.2016.09.002
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发表时间：
2017-05
期刊：
影响因子：
--
通讯作者：
Amizuka N
中科院分区：
文献类型：
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作者：
Hasegawa T;Yamamoto T;Tsuchiya E;Hongo H;Tsuboi K;Kudo A;Abe M;Yoshida T;Nagai T;Khadiza N;Yokoyama A;Oda K;Ozawa H;de Freitas PHL;Li M;Amizuka N
基质囊泡介导的矿化是导致晶体成核和生长的超微结构和生物化学事件的协调序列。磷酸根离子流入基质囊泡是由几种蛋白质如TNAP、ENPP 1、Pit 1、膜联蛋白等介导的。ENPP 1的催化活性使用细胞外ATP作为底物产生焦磷酸盐（PPi），并且所得PPi防止晶体过度生长。然而，TNAP将PPi水解成磷酸根离子单体，然后通过Pit 1转运到基质囊泡中。Ca2+和PO43−在基质囊泡内的积累然后诱导结晶成核，磷酸钙晶体放射状出芽，刺穿基质囊泡的膜，最后从膜中生长出来形成矿化结节。
Matrix vesicle-mediated mineralization is an orchestrated sequence of ultrastructural and biochemical events that lead to crystal nucleation and growth. The influx of phosphate ions into the matrix vesicle is mediated by several proteins such as TNAP, ENPP1, Pit1, annexin and so forth. The catalytic activity of ENPP1 generates pyrophosphate (PPi) using extracellular ATPs as a substrate, and the resultant PPi prevents crystal overgrowth. However, TNAP hydrolyzes PPi into phosphate ion monomers, which are then transported into the matrix vesicle through Pit1. Accumulation of Ca2+ and PO43− inside matrix vesicles then induces crystalline nucleation, with calcium phosphate crystals budding off radially, puncturing the matrix vesicle’s membrane and finally growing out of it to form mineralized nodules.