Felix R, Fleisch H
Calcif Tissue Res. 1976 Nov 24;22(1):1-7. doi: 10.1007/BF02010340.
Some of the characteristics of the pyrophosphatase and ATPase activities studied in isolated cartilage matrix vesicles were found to be similar to those already reported for the solubilized and purified bone alkaline phosphatase. Thus, the pH optimum of the pyrophosphatase activity responded similarly to changes in the concentration of Mg2+, Ca2+, and PPi. Further, the ATPase activity was not activated by Ca2+ in the presence of an optimal Mg2+ concentration. It is proposed that a function of the alkaline phosphatase of matrix vesicles in vivo is to hydrolyze the substrates PPi, ADP, and ATP, which are known inhibitors of calcium phosphate precipitation.
在分离出的软骨基质小泡中所研究的焦磷酸酶和ATP酶活性的某些特征，被发现与已报道的溶解并纯化的骨碱性磷酸酶的特征相似。因此，焦磷酸酶活性的最适pH对Mg2+、Ca2+和PPi浓度的变化有类似的反应。此外，在存在最佳Mg2+浓度的情况下，Ca2+不会激活ATP酶活性。有人提出，基质小泡的碱性磷酸酶在体内的功能是水解底物PPi、ADP和ATP，这些都是已知的磷酸钙沉淀抑制剂。
