Mazurkiewicz J E, Hossler F E, Barrnett R J
J Histochem Cytochem. 1978 Dec;26(12):1042-52. doi: 10.1177/26.12.215672.
A cytochemical probe for the ultrastructural localization of the NaKATPase was devised, which utilizes the biological affinity of the noncompetitive inhibitor, ouabain (ouab) to which was coupled a hemepeptide (H11P) which possesses peroxidatic activity. The conjugate, ouab-H11P, had an apparent Ki of approximately 8 x 10(-7) M. When reacted with fixed tissue from the salt gland of osmotically stressed ducklings, the NaKATPase was localized to the basal and lateral infoldings of the plasma membranes of secretory epithelial cells. Reaction product consisted of fine textured deposits distributed in focal patches on the outer aspects of the membrane. Apical membranes were negative, as were intracellular membrane components. Preincubation of tissue with unlabeled ouabain or binding of ouab-H11P in the presence of 10 mM K+, no ATP and no Mg++, resulted in the absence or diminution of reaction product.
设计了一种用于钠钾ATP酶超微结构定位的细胞化学探针，它利用非竞争性抑制剂哇巴因（ouab）的生物亲和力，将具有过氧化物酶活性的血红素肽（H11P）与之偶联。偶联物ouab-H11P的表观抑制常数（Ki）约为8×10⁻⁷ M。当与渗透应激雏鸭盐腺的固定组织反应时，钠钾ATP酶定位于分泌上皮细胞质膜的基底和侧褶处。反应产物由分布在膜外侧局部斑块中的精细纹理沉积物组成。顶端膜呈阴性，细胞内膜成分也是如此。用未标记的哇巴因对组织进行预孵育，或在存在10 mM钾离子、无ATP和无镁离子的情况下使ouab-H11P结合，会导致反应产物缺失或减少。
