Glycosylation of Asn-632 and Asn-651 is important for functional expression of endothelin-converting enzyme-1.

It has been shown previously that N-glycosylation of Asn-144 and/or Asn-627 is important for functional expression of neutral endopeptidase-24.11 (NEP). All glycosylation sites of NEP are conserved within endothelin-converting enzyme-1 (ECE-1). In the present study we investigated the importance of proper glycosylation for the biologic function of ECE-1. We show that the double mutation of Asn-632 and Asn-651 leads to expression of an enzymatically inactive ECE-1 protein. In contrast, the single mutation of either Asn-632 or Asn-651 did not alter the enzymatic activity of ECE-1b.