ISOZYMES OF NA+/K+ ATPASE--MONOCLONAL ANTIBODY PROBES

已知心脏糖苷引起的变力作用是由于 抑制Na，K-ATP酶。 这个实验室发现了 脑中存在Na，K-ATP酶同工型， 在某些情况下， 物种 在支持的第一阶段，单克隆抗体 的Na，K-ATP酶，允许鉴定三个 心脏中的同种型。 单克隆抗体表位为 映射;用于确定特异性;并用于研究 跨膜蛋白地形图 然后他们被用来评估 控制大鼠中同种型表达的因子 心 在发育、甲状腺功能减退和 高血压对于了解心脏的 对药物的生理敏感性。 现在的目标是使用单克隆抗体表位作图， 研究Na，K-ATP酶异构体的结构。 抗体 将有助于同种型变体的生化分析。 他们将 用于确定跨膜片段的形貌， 有争议的C端 他们也将习惯于 推断哇巴因结合位点的位置 这样的物理 证据补充和测试模型支持的分子 生物学;例如，我们有证据表明， 站点未位于站点指向的 诱变

Cardiac glycoside-elicited inotropy is known to be due to inhibition of the Na,K-ATPase. This laboratory discovered the existence of Na,K-ATPase isoforms in the brain, and that they had markedly different affinities for cardiac glycosides in some species. In the first period of support, monoclonal antibodies were produced that permitted identification of three Na,K-ATPase isoforms in the heart. The monoclonal antibody epitopes were mapped; used to determine specificity; and used to study transmembrane protein topography. They then were used to assess factors that control the expression of the isoforms in the rat heart. Changes were seen during development, hypothyroidism, and hypertension that are important for understanding the heart's physiological sensitivity to the drug. The objective now is to use monoclonal antibody epitope mapping to investigate the structure of the Na,K-ATPase isoforms. Antibodies will aid the biochemical analysis of isoform variants. They will be used to determine the topography of transmembrane segments in the controversial C-terminal half. They will also be used to deduce the location of the ouabain binding site. Such physical evidence complements and tests models supported by molecular biology; for example, we have evidence that the ouabain binding site is not located at the position indicated by site-directed mutagenesis.