Large‐scale purification of functional recombinant human aquaporin‐2
Tóm tắt
The homotetrameric aquaporin‐2 (AQP2) water channel is essential for the concentration of urine and of critical importance in diseases with water dysregulation, such as nephrogenic diabetes insipidus, congestive heart failure, liver cirrhosis and pre‐eclampsia. The structure of human AQP2 is a prerequisite for understanding its function and for designing specific blockers. To obtain sufficient amounts of AQP2 for structural analyses, we have expressed recombinant his‐tagged human AQP2 (HT‐AQP2) in the baculovirus/insect cell system. Using the protocols outlined in this study, 0.5 mg of pure HT‐AQP2 could be obtained per liter of bioreactor culture. HT‐AQP2 had retained its homotetrameric structure and exhibited a single channel water permeability of 0.93±0.03×10−13 cm3/s, similar to that of other AQPs. Thus, the baculovirus/insect cell system allows large‐scale expression of functional recombinant human AQP2 that is suitable for structural studies.