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

NA /K ATP酶同工酶--单克隆抗体探针

• 批准号: 2218112
• 负责人: Kathleen J Sweadner
• 金额: $ 23.67万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 1997-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2218112
• 关键词: active sites; antibody formation; enzyme activity; enzyme structure; epitope mapping; gene expression; heart cell; high performance liquid chromatography; hybridomas; immunocytochemistry; isozymes; laboratory mouse; laboratory rat; monoclonal antibody; muscle cells; ouabain; protein sequence; sodium potassium exchanging ATPase; tissue /cell culture

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.

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