Oxidative alterations of proteins by reactive oxygen species (ROS) have been implicated in the progression of aging and age-related neurodegenerative disorders such as Alzheimer's disease (AD). Protein carbonyls, a marker of protein oxidation, are increased in AD brain, indicating that oxidative modification of proteins is relevant in AD. Oxidative damage can lead to several events such as loss in specific protein function, abnormal protein clearance, depletion of the cellular redox-balance and interference with the cell cycle, and, ultimately, to neuronal death. Identification of specific targets of protein oxidation represents a crucial step in establishing a relationship between oxidative modification and neuronal death in AD, and was partially achieved previously in our laboratory through immunochemical detection of creatine kinase BB and β-actin as specifically oxidized proteins in AD brain versus control brain. However, this process is laborious, requires the availability of specific antibodies, and, most importantly, requires a reasonable guess as to the identity of the protein in the first place. In this study, we present the first proteomics approach to identify specifically oxidized proteins in AD, by coupling 2D fingerprinting with immunological detection of carbonyls and identification of proteins by mass spectrometry. The powerful techniques, emerging from application of proteomics to neurodegenerative disease, reveal the presence of specific targets of protein oxidation in Alzheimer's disease (AD) brain: creatine kinase BB, glutamine synthase, and ubiquitin carboxy-terminal hydrolase L-1. These results are discussed with reference to potential involvement of these oxidatively modified proteins in neurodegeneration in AD brain. Proteomics offers a rapid means of identifying oxidatively modified proteins in aging and age-related neurodegenerative disorders without the limitations of the immunochemical detection method.
|Number of pages||10|
|Journal||Free Radical Biology and Medicine|
|State||Published - Aug 15 2002|
Bibliographical noteFunding Information:
We thank the University of Kentucky ADRC core facility for providing the brain tissue used for this study. This work was supported in part by grants from NIH to D.A.B. [AG-05119; AG-10836; AG-12423], NIH to J.B.K. [R01 HL66358-01], a Department Of Veterans Affairs Merit Research Grant, (J.B.K.), a NIH grant to W.R.M. [5 P50 AG-05144], and a grant from the Abercrombie Foundation to W.R.M.
- Alzheimer's disease
- Free radicals
- Mass spectrometry
- Oxidative stress
- Protein oxidation
ASJC Scopus subject areas
- Physiology (medical)