Wakui H, Komatsuda A, Kodama T, Mamiya S, Miura A B
3rd Department of Internal Medicine, Akita University School of Medicine, Japan.
Ren Physiol Biochem. 1995 May-Jun;18(3):109-17. doi: 10.1159/000173908.
We have purified a 17-kD puromycin aminonucleoside (PAN) binding protein from porcine kidney and identified it as the reported 17-kD protein kinase C inhibitor on the basis of its partial amino acid sequence. Of 54 determined amino acid sequences of the 17-kD porcine renal protein, 51 residues were identical to those of the 17-kD bovine brain protein kinase C inhibitor. However, our purified protein did not carry the inhibitory activity on protein kinase C. Immunohistochemical studies showed a unique intrarenal distribution of the 17-kD PAN-binding protein at the apical side of epithelial cells of Henle's loops in the inner medulla and of distal convoluted tubules. Immunoblot analysis revealed that the 17-kD PAN-binding protein was extractable by an isotonic buffer without sodium deoxycholate extraction. These results suggest that this protein binds loosely to the apical membranes of epithelial cells of Henle's loops and distal tubules and has specific functions related to tubular functions of these nephron segments at the apical side. Whether this protein is a real inhibitor of protein kinase C or not remains to be investigated.
我们从猪肾中纯化了一种17-kD嘌呤霉素氨基核苷（PAN）结合蛋白，并根据其部分氨基酸序列将其鉴定为已报道的17-kD蛋白激酶C抑制剂。在17-kD猪肾蛋白的54个已确定氨基酸序列中，有51个残基与17-kD牛脑蛋白激酶C抑制剂的残基相同。然而，我们纯化的蛋白对蛋白激酶C没有抑制活性。免疫组织化学研究显示，17-kD PAN结合蛋白在内髓亨氏袢上皮细胞和远曲小管上皮细胞顶端侧有独特的肾内分布。免疫印迹分析表明，17-kD PAN结合蛋白可用不含脱氧胆酸钠提取的等渗缓冲液提取。这些结果表明，该蛋白与亨氏袢和远曲小管上皮细胞的顶端膜松散结合，并在顶端侧具有与这些肾单位节段的肾小管功能相关的特定功能。该蛋白是否为真正的蛋白激酶C抑制剂仍有待研究。
