Wöltgens J H, Bervoets T J, Lyaruu D M, Bronckers A L
Department of Oral Cell Biology, Academic Center for Dentistry, Amsterdam, The Netherlands.
Arch Oral Biol. 1989;34(7):591-2. doi: 10.1016/0003-9969(89)90101-5.
p-Nitrophenyl phosphatase (p-NPP-ase) and inorganic pyrophosphatase (PPi-ase) activities originate from the same alkaline phosphatase enzyme. Only the PPi-ase site has zinc (Zn2+) as a cofactor. Cadmium (Cd2+) in concentrations from 10(-5) mol/l upwards inhibited the PPi-ase activity, but did not inhibit the p-NPP-ase activity at all. In mineralizing tooth germs Cd2+ may replace Zn2+, thereby changing the specific stereoconfiguration in the active centre needed for PPi-ase activity, but not that for p-NPP-ase activity.
对硝基苯磷酸酶（p-NPP-ase）和无机焦磷酸酶（PPi-ase）活性源自同一种碱性磷酸酶。只有PPi-ase位点有锌（Zn2+）作为辅助因子。浓度从10^(-5) mol/l及以上的镉（Cd2+）抑制PPi-ase活性，但对p-NPP-ase活性完全没有抑制作用。在矿化牙胚中，Cd2+可能取代Zn2+，从而改变PPi-ase活性所需的活性中心的特定立体构型，但不会改变p-NPP-ase活性所需的立体构型。
