Catechol-O-methyl transferase in mouse liver plasma membranes. |
| |
Authors: | J R Aprille D F Malamud |
| |
Institution: | From the Pediatric and Surgical Services, Shriners Burns Institute and the Massachusetts General Hospital, and the Departments of Pediatrics and Surgery, Harvard Medical School USA |
| |
Abstract: | Catechol-o-methyl transferase is usually localized predominantly in the cytosol fraction of cells, but fractionation of mouse liver showed plasma membranes contain ~ 70% of the total enzyme activity and have a specific activity ~ 10x greater than the cytosol fraction. Treatment of the membrane fraction with Lubrol-PX solubilized 47% of the membrane protein and 95% of the enzyme activity. A comparison of Lubrol-solubilized enzyme and 3H]norepinephrine binding activities in a variety of experimental conditions suggest binding is not related to interaction with the active site of catechol-o-methyl transferase. Isoelectric focusing of solubilized membrane proteins showed the enzyme has an isoelectric pH of 4.5-4.8. |
| |
Keywords: | Address reprint requests to: Shriners Burns Institute 50 Blossom St Boston MA 02114USA |
本文献已被 ScienceDirect 等数据库收录! |