Development of a capillary isoelectric focusing immunoassay to measure DJ-1 isoforms in biological samples.
We report on the development of a novel assay protocol for the separation and detection of charge isoforms of DJ-1 in biological samples by automated capillary isoelectric focusing followed by immunological detection. DJ-1 (PARK7) is considered as a biomarker candidate for Parkinson's disease and may potentially support the differentiation of clinical subtypes of the disease. The new method allows for separation and subsequent relative quantitative comparison of different isoforms of DJ-1 in biological samples. The assay was successfully applied to the analysis of DJ-1 isoform patterns in brains from mice subjected to normal or high-fat diet and revealed statistically significant group differences. Furthermore, in a pooled and concentrated sample of human cerebrospinal fluid that was depleted of albumin and immunoglobulin G, four different charge variants of DJ-1 could be detected. Taken together, the capillary isoelectric focusing immunoassay for DJ-1 represents a promising tool that may ultimately serve in clinical biomarker studies.
LVR-Hospital Essen, Department of Psychiatry and Psychotherapy, Faculty of Medicine, University of Duisburg-Essen, 45147 Essen, Germany.
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D
Besong Agbo
H
H
Klafki
G
G
Poschmann
K
K
Seyfarth
J
J
Genius
C
C
Janßen
K
K
Stühler
W
W
Wurst
H E
HE
Meyer
M
M
Klingenspor
J
J
Wiltfang
D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism; D001923:Brain Chemistry; D059305:Diet, High-Fat; D006801:Humans; D007118:Immunoassay / Q000379:methods; D047908:Intracellular Signaling Peptides and Proteins / Q000134:cerebrospinal fluid*; D007525:Isoelectric Focusing / Q000379:methods*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D015513:Oncogene Proteins / Q000032:analysis* / Q000134:cerebrospinal fluid* / Q000378:metabolism; D010300:Parkinson Disease / Q000134:cerebrospinal fluid*; D054464:Peroxiredoxins; D000071617:Protein Deglycase DJ-1; D020033:Protein Isoforms / Q000032:analysis / Q000134:cerebrospinal fluid
D047908:Intracellular Signaling Peptides and Proteins; D015513:Oncogene Proteins; D020033:Protein Isoforms; D054464:Peroxiredoxins; C105131:PARK7 protein, human; C503466:PARK7 protein, mouse; D000071617:Protein Deglycase DJ-1
Biomarker; CSF; DJ-1; Immunoassay; Isoelectric focusing; PARK7