Glycosylation variants of endopeptidase-24.11 ('enkephalinase')

T. A. Vida, L. B. Hersh

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Anion exchange chromatography resolves two charge variants of rat kidney endopeptidase-24.11 (designated NEP 1 and NEP 2); each was purified to homogeneity using immunoaffinity chromatography. In addition to charge differences the subunit molecular weights of NEP 1 and NEP 2 differ and are 89 and 96 kDa, respectively. Isoelectric focusing resolved 8-10 pl species in the pH range of 5.95 - 6.20 for NEP 1 and 5.46 - 6.06 for NEP 2. Removal of sialic acid residues converted the multiple pl species to one form with a pl of 6.32 for NEP 2, and two forms with pls of 6.27 and 6.32 for NEP 1. Endoglycosidase H or F, capable of removing high-mannose and biantennary branched N-linked oligosaccharides, produced a 2-3 kDa decrease in the molecular weight of both NEP 1 and NEP 2. Peptide-N-glycosidase F, capable of removing all classes of N-linked oligosaccharides, produced 8 and 11 kDa decreases in NEP 1 and NEP 2, respectively. Removal of all N-linked and O-linked oligosaccharides with trifluoromethanesulfonic acid resulted in 10 and 15 kDa decreases in NEP 1 and NEP 2, respectively. Tryptic epitope maps demonstrated that NEP 2 was cleaved at a slower rate than NEP 1. These analyses demonstrate that rat kidney NEP exhibits sialic acid microheterogeneity resulting in two distinct change variants. The data also indicate that NEP 2 contains more N- and O-linked carbohydrate mass than NEP 1 and may contain a larger polypeptide backbone giving rise to molecular weight differences between these enzyme forms.

Original languageEnglish
Pages (from-to)245-255
Number of pages11
Issue number4
StatePublished - Apr 1992

Bibliographical note

Funding Information:
This research was supported in part by Grant #DA02243 (NIH) and Grant #I-391 (The Robert A. Welch Foundation, Houston, Texas). TAV was ar ecipient ofa USPHS traineeship #GM07062.

ASJC Scopus subject areas

  • Endocrinology
  • Neurology
  • Endocrine and Autonomic Systems
  • Cellular and Molecular Neuroscience


Dive into the research topics of 'Glycosylation variants of endopeptidase-24.11 ('enkephalinase')'. Together they form a unique fingerprint.

Cite this