Fig. 2.

Effect of crosslinkers on NCX1 mobility. All exchangers were engineered to have only two cysteine residues. One cysteine was in the N-terminal half and the other in the C-terminal portion of the protein; for example, the notation 20C/825C indicates the use of an NCX1 with cysteines located at positions 20 and 825 (see Fig. 1). Shown are immunoblots for NCX1 protein of cellular homogenates. Suspended cells were incubated with CuPhe (1 mM), 3M (0.5 mM), or PEG2 (1 mM) for 20 min at 20° C. Disulfide bond formation results in a shift in the apparent mobility of NCX1 from 120 to 140 kDa.