Glutaminyl cyclase activity is a characteristic feature of human cerebrospinal fluid

Proteins and peptides occurring in human body fluids can be useful biological markers for neurological diseases and can even contribute to the pathogenesis of such diseases. However, proteins and peptides are potential substrates of proteases and other enzymes. Proteolysis and enzymatic modification...

Full description

Saved in:
Bibliographic Details
Published in:Clinica chimica acta 2008-03, Vol.389 (1-2), p.152-159
Main Authors: Gontsarova, Anastassia, Kaufmann, Eckhard, Tumani, Hayrettin, Dressel, Alexander, Mandel, Friedrich, Wiesmüller, Karl-Heinz, Kunert-Keil, Christiane, Brinkmeier, Heinrich
Format: Article
Language:English
Subjects:
Aminoacyltransferases - cerebrospinal fluid
Biomarkers - cerebrospinal fluid
Chromatography, High Pressure Liquid
Humans
Mass Spectrometry
Multiple Sclerosis - cerebrospinal fluid
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Proteins and peptides occurring in human body fluids can be useful biological markers for neurological diseases and can even contribute to the pathogenesis of such diseases. However, proteins and peptides are potential substrates of proteases and other enzymes. Proteolysis and enzymatic modification may lead to their degradation and modification. Using mass spectrometry we investigated the degradation and modification of indicator peptides in the presence of cerebrospinal fluid (CSF). We further applied a fluorometric assay to study the activity of the presumed enzyme glutaminyl cyclase. In CSF we observed an aminopeptidase activity that could partially be inhibited by protease inhibitors and EDTA. In addition, the formation of pyroglutamate (pGlu) from N-terminal glutamine (Gln) was regularly observed. The reaction to pGlu was rapid and protected the indicator peptides from further N-terminal degradation. The conversion of Gln to pGlu could be attributed to the activity of the enzyme glutaminyl cyclase (QC). The QC activity was a characteristic feature of all 45 CSF samples collected from multiple sclerosis patients and controls. Glutaminyl cyclase activity is a characteristic feature of human cerebrospinal fluid. The presence of QC in CSF can stabilize peptides from degradation by aminopeptidases. This may have impact for neurological disorders that are characterized by both, the presence of QC and the occurrence of appropriate peptide substrates.
ISSN:0009-8981
1873-3492
DOI:10.1016/j.cca.2007.12.010