Development of a capillary isoelectric focusing immunoassay to measure DJ-1 isoforms in biological samples

Anal Biochem. 2013 Dec 15;443(2):197-204. doi: 10.1016/j.ab.2013.09.013. Epub 2013 Sep 17.

Abstract

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.

Keywords: Biomarker; CSF; DJ-1; Immunoassay; Isoelectric focusing; PARK7.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Brain / metabolism
  • Brain Chemistry*
  • Diet, High-Fat
  • Humans
  • Immunoassay / methods
  • Intracellular Signaling Peptides and Proteins / cerebrospinal fluid*
  • Isoelectric Focusing / methods*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Oncogene Proteins / analysis*
  • Oncogene Proteins / cerebrospinal fluid*
  • Oncogene Proteins / metabolism
  • Parkinson Disease / cerebrospinal fluid*
  • Peroxiredoxins
  • Protein Deglycase DJ-1
  • Protein Isoforms / analysis
  • Protein Isoforms / cerebrospinal fluid

Substances

  • Intracellular Signaling Peptides and Proteins
  • Oncogene Proteins
  • Protein Isoforms
  • Peroxiredoxins
  • PARK7 protein, human
  • PARK7 protein, mouse
  • Protein Deglycase DJ-1