Soluble and Catalytically Active Endothelin Converting Enzyme-1 is Present in Cerebrospinal Fluid of Subarachnoid Hemorrhage Patients

Sanjaya Kuruppu*, Sherry H.Y. Chou, Steven K. Feske, Sarah Suh, Iresha Hanchapola, Eng H. Lo, Ming Ming Ning, A. Ian Smith

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

Endothelin converting Enzyme-1 (ECE-1) is essential for the production of Endothelin-1 (ET-1), which is associated with vasospasm following subarachnoid hemorrhage (SAH). We have previously demonstrated the presence of a catalytically active soluble form of ECE-1 in the media of endothelial cells. We aimed to determine if this form of ECE-1 exists in vivo, in cerebrospinal fluid (CSF) of SAH patients. We examined CSF taken from SAH subjects for the presence of soluble ECE-1 using a bradykinin based quenched fluorescent substrate assay. We obtained further confirmation by characterizing the CSF mediated cleavage products of BigET-1 and BigET18-34 (6 βg/ml) using mass spectrometry. The specificity of cleavage was confirmed using the ECE-1 inhibitor CGS35066 5nmol/L. SAH CSF samples had mean ECE-1 activity of 0.127 0.037 βmols of substrate cleaved/βl of CSF/24 h. The C-terminal peptides generated upon the cleavage of BigET-1 and BigET18-34 were detected 48 h after incubation of these substrates with CSF. Cleavage of these substrates was inhibited by CGS35066. Results of Western blots also produced strong evidence for the presence of truncated soluble ECE-1 in CSF. These results strongly suggest the presence of a truncated but catalytically active form of ECE-1 in the CSF of SAH subjects. Further studies are necessary to determine the biological significance of soluble ECE-1 in CSF of SAH subjects, including an association with vasospasm after SAH.

Original languageEnglish (US)
Pages (from-to)1091-1094
Number of pages4
JournalMolecular and Cellular Proteomics
Volume13
Issue number4
DOIs
StatePublished - Apr 2014
Externally publishedYes

ASJC Scopus subject areas

  • Analytical Chemistry
  • Molecular Biology
  • Biochemistry

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