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Oxidative Medicine and Cellular Longevity
Volume 2011, Article ID 213686, 8 pages
http://dx.doi.org/10.1155/2011/213686
Research Article

4-Hydroxy-2-Nonenal-Modified Glyceraldehyde-3-Phosphate Dehydrogenase Is Degraded by Cathepsin G in Rat Neutrophils

1Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan
2Department of Hygienic Chemistry, Showa Pharmaceutical University, 3-3165 Higashi-Tamagawagakuen, Machida, Tokyo 194-8543, Japan
3Department of Analytical Chemistry of Medicines, Showa Pharmaceutical University, 3-3165 Higashi-Tamagawagakuen, Machida, Tokyo 194-8543, Japan

Received 26 November 2010; Accepted 17 January 2011

Academic Editor: Kenneth Maiese

Copyright © 2011 Yukihiro Tsuchiya et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Degradation of oxidized or oxidatively modified proteins is an essential part of the antioxidant defenses of cells. 4-Hydroxy-2-nonenal, a major reactive aldehyde formed by lipid peroxidation, causes many types of cellular damage. It has been reported that 4-hydroxy-2-nonenal-modified proteins are degraded by the ubiquitin-proteasome pathway or, in some cases, by the lysosomal pathway. However, our previous studies using U937 cells showed that 4-hydroxy-2-nonenal-modified glyceraldehyde-3-phosphate dehydrogenase is degraded by cathepsin G. In the present study, we isolated the 4-hydroxy-2-nonenal-modified glyceraldehyde-3-phosphate dehydrogenase-degrading enzyme from rat neutrophils to an active protein fraction of 28 kDa. Using the specific antibody, the 28 kDa protein was identified as cathepsin G. Moreover, the degradation activity was inhibited by cathepsin G inhibitors. These results suggest that cathepsin G plays a crucial role in the degradation of 4-hydroxy-2-nonenal-modified glyceraldehyde-3-phosphate dehydrogenase.