Characterisation of the purified human sodium/iodide symporter reveals that the protein is mainly present in a dimeric form and permits the detailed study of a native C-terminal fragment

►The human sodium/iodide symporter (NIS) has been purified for the first time. ►NIS protein exists mainly as a dimer that is stabilised by a disulfide bridge. ►A proteolytic C-terminal fragment of NIS is present in quantity in various species. ►Co-expression of C- and N-terminal fragments reconstitute a functional NIS.