Moy T C, Walters J R, Weiser M M
Biochem Biophys Res Commun. 1986 Dec 30;141(3):979-85. doi: 10.1016/s0006-291x(86)80140-1.
The Ca-pump in rat intestinal basolateral membranes had been studied previously as vesicular ATP-dependent Ca-uptake. In the present studies, Ca-stimulated ATP hydrolysis (Ca-ATPase activity) was measured and found to differ from the Ca-pump in having higher activity and being insensitive to vanadate. Whereas the pump was specific for ATP, hydrolytic activity was found with ATP, GTP or ADP but not with AMP or p-nitro-phenyl-phosphate. In contrast to Ca-pump activity, Ca-ATPase activities were similar for different intestinal segments, for duodenal villus/crypt cell-fractions and for vitamin D-deficient animals. Thus, as usually measured, intestinal basolateral membrane Ca-ATPase activity is not equivalent to the Ca-pump.
大鼠肠基底外侧膜中的钙泵先前已作为囊泡ATP依赖性钙摄取进行了研究。在本研究中，测量了钙刺激的ATP水解（钙ATP酶活性），发现其与钙泵不同，具有更高的活性且对钒酸盐不敏感。虽然该泵对ATP具有特异性，但发现ATP、GTP或ADP具有水解活性，而AMP或对硝基苯磷酸则没有。与钙泵活性相反，不同肠段、十二指肠绒毛/隐窝细胞组分以及维生素D缺乏动物的钙ATP酶活性相似。因此，通常所测量的肠基底外侧膜钙ATP酶活性并不等同于钙泵。
