Expression of ECE and related membrane peptidases in the EA.hy926 cell line

The membrane anchorage of endothelin-converting enzyme (ECE) and endopeptidase E-24.11 (E-24.11) was investigated using the human endothelial cell line EA.hy926 as a model system. Detergent solubilization and temperature-induced phase separation data were consistent with recently published ECE sequences in characterizing ECE as an integral membrane protein. With GK4A9, a monoclonal antibody raised to E-24.11, more than 75% of total ECE activity could be precipitated from a membrane fraction, indicating a common epitope between ECE and E-24.11.