Kinetic analysis of substrate utilization by native and TNAP-, NPP1-, or PHOSPHO1-deficient matrix vesicles.
Kinetic analysis of substrate utilization by native and TNAP-, NPP1-, or PHOSPHO1-deficient matrix vesicles.
复制标题
DOI：
10.1359/jbmr.091023
复制
发表时间：
2010-04
期刊：
影响因子：
--
通讯作者：
Millán JL
中科院分区：
文献类型：
--
作者：
Ciancaglini P;Yadav MC;Simão AM;Narisawa S;Pizauro JM;Farquharson C;Hoylaerts MF;Millán JL
在软骨内骨形成过程中，软骨细胞和成骨细胞通过促进膜限制性基质囊泡（MV）内部的羟基磷灰石晶种形成来矿化其细胞外基质。在这里，我们研究了磷酸化底物催化成骨细胞衍生的MV在生理pH值，分析ATP，ADP和PPi的水解分离的野生型（WT）以及TNAP，NPP1和PHOSPHO1缺陷的MV。催化效率的比较确定ATP为WT MV水解的主要底物。TNAP的缺乏对所有生理底物的水解具有最显著的影响。缺乏PHOSPHO1影响ATP水解，通过二次减少TNAP水平的PHOSPHO1缺乏MV。对于任何底物，与WT MV相比，NPP 1的缺乏均未显著影响水解的动力学参数。我们得出结论，TNAP是酶，水解ATP和PPi在MV室。NPP 1在MV水平上从ATP产生PPi中没有主要作用，与其在成骨细胞和软骨细胞表面上的公认作用相反，而是在TNAP不存在的情况下充当磷酸酶。© 2010美国骨与矿物质研究学会。
During the process of endochondral bone formation, chondrocytes and osteoblasts mineralize their extracellular matrix by promoting the formation of hydroxyapatite seed crystals in the sheltered interior of membrane-limited matrix vesicles (MVs). Here, we have studied phosphosubstrate catalysis by osteoblast-derived MVs at physiologic pH, analyzing the hydrolysis of ATP, ADP, and PPi by isolated wild-type (WT) as well as TNAP-, NPP1- and PHOSPHO1-deficient MVs. Comparison of the catalytic efficiencies identified ATP as the main substrate hydrolyzed by WT MVs. The lack of TNAP had the most pronounced effect on the hydrolysis of all physiologic substrates. The lack of PHOSPHO1 affected ATP hydrolysis via a secondary reduction in the levels of TNAP in PHOSPHO1-deficient MVs. The lack of NPP1 did not significantly affect the kinetic parameters of hydrolysis when compared with WT MVs for any of the substrates. We conclude that TNAP is the enzyme that hydrolyzes both ATP and PPi in the MV compartment. NPP1 does not have a major role in PPi generation from ATP at the level of MVs, in contrast to its accepted role on the surface of the osteoblasts and chondrocytes, but rather acts as a phosphatase in the absence of TNAP. © 2010 American Society for Bone and Mineral Research.
登录
查看更多内容
影响因子：
6
作者：
Anderson, HC;Harmey, D;Millán, JL
通讯作者：
Millán, JL
影响因子：
4.3
作者：
Pizauro, JM;Ciancaglini, P;Leone, FA
通讯作者：
Leone, FA
影响因子：
3.4
作者：
Pizauro, JM;Demenis, MA;Leone, FA
通讯作者：
Leone, FA
影响因子：
6
作者：
Harmey, D;Hessle, L;Millán, JL
通讯作者：
Millán, JL
DOI：
10.1073/pnas.142063399
发表时间：
2002-07-09
影响因子：
11.1
作者：
Hessle, L;Johnson, KA;Millán, JL
通讯作者：
Millán, JL