The Na + /H + exchanger is a ubiquitous membrane protein of bacteria, plants and mammals. The first isoform discov-ered (NHE1) is present on the mammalian plasma mem-brane and transports oneH + out of cells inexchange for one extracellular Na + . With solubilization in standard SDS/ PAGE buffer, this protein had a high tendency to aggregate when subjected to elevated temperature. The aggregates were stable and did not dissociate in high concentrations of SDSor 2-mercaptoethanol.
