Parys J B, De Smedt H, Vandenberghe P, Borghgraef R
Cell Calcium. 1985 Oct;6(5):413-29. doi: 10.1016/0143-4160(85)90018-1.
ATP-driven calcium uptake was studied in basal-lateral membranes and in microsomal fractions, isolated from pig kidney cortex. The uptake is strongly enhanced in conditions where calcium inside the vesicles is precipitated by oxalate (5 mM) or phosphate (40 mM). Both anions were equally effective for the stimulation of calcium uptake in the microsomes but oxalate was less effective than phosphate in the basal-lateral membrane fraction. The active calcium pumps in the renal basal-lateral and microsomal fractions are different transport ATPases characterized by phosphorylated intermediates of 135 kDa and 115 kDa respectively. The subcellular distribution of the 135 kDa and 115 kDa phosphointermediates, reflects the distribution of typical marker enzymes for the basal-lateral membrane and for the endoplasmic reticulum. The calmodulin binding to the 135 kDa polypeptide as estimated by 125I-labelled calmodulin overlay, can be used as a specific marker for the basal-lateral plasma membrane calcium pump.
对从猪肾皮质分离出的基底外侧膜和微粒体部分中的ATP驱动钙摄取进行了研究。在囊泡内的钙被草酸盐（5 mM）或磷酸盐（40 mM）沉淀的条件下，摄取显著增强。两种阴离子在刺激微粒体中的钙摄取方面同样有效，但草酸盐在基底外侧膜部分中比磷酸盐的效果要差。肾基底外侧和微粒体部分中的活性钙泵是不同的转运ATP酶，其特征分别是具有135 kDa和115 kDa的磷酸化中间体。135 kDa和115 kDa磷酸中间体的亚细胞分布反映了基底外侧膜和内质网典型标记酶的分布。通过125I标记的钙调蛋白覆盖法估计，钙调蛋白与135 kDa多肽的结合可用作基底外侧质膜钙泵的特异性标记。
