Description:
<jats:sec><jats:label /><jats:p>Band 3 is the most abundant membrane protein in human red cells. Band 3 primarily functions as a bi‐directional anion transporter for Cl<jats:sup>−</jats:sup> and HCO<jats:sub>3</jats:sub><jats:sup>−</jats:sup> to support blood CO<jats:sub>2</jats:sub> exchange. Because CO<jats:sub>2</jats:sub> mainly exists in the form of HCO<jats:sub>3</jats:sub><jats:sup>−</jats:sup> <jats:sub>(aq)</jats:sub> in the human body, the rate of CO<jats:sub>2</jats:sub> blood respiration is dependent on the intraerythrocytic reaction CO<jats:sub>2(g)</jats:sub> + H<jats:sub>2</jats:sub>O □ HCO<jats:sub>3</jats:sub><jats:sup>−</jats:sup> <jats:sub>(aq)</jats:sub> + H<jats:sup>+</jats:sup> <jats:sub>(aq)</jats:sub>. By FLIM‐FRET, we recently uncovered the existence of mobile interaction between band 3 and water channel AQP1. Their interaction could be disrupted when red cell vesicles were put in a hypotonic milieu, suggesting AQP1 bearing a functional role in the band 3‐central CO<jats:sub>2</jats:sub> transport metabolon.</jats:p></jats:sec><jats:sec><jats:title>Objective</jats:title><jats:p>As there are at least two types of band 3 protein complexes on the erythrocyte membrane, the goal of this study was to probe the physical associations between aquaporins and different band 3 complexes.</jats:p></jats:sec><jats:sec><jats:title>Method</jats:title><jats:p>We utilized semi‐native and native gel electrophoresis to identify aquaporin complexes and to differentiate their associations with the different band 3 complexes.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Water channel AQP1 and aquaglyceroporin AQP3 complexes were both identified in red cell ghosts by semi‐native gel electrophoresis. Some of the aquaporin complexes were found to be structurally linked to band 3 protein complexes.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>The physical association between AQP1 and band 3 and that between AQP3 and band 3 can be differentiated by semi‐native gel electrophoresis. Erythrocyte aquaporins also appear physically linked to other membrane‐associated proteins in the human red cells.</jats:p><jats:p><jats:bold>Support or Funding Information</jats:bold></jats:p><jats:p>MOST 106‐2320‐B‐195‐002 from Taiwan Ministry of Science & Technology</jats:p><jats:p>This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in <jats:italic>The FASEB Journal</jats:italic>.</jats:p></jats:sec>