The ceruloplasmin and hydrogen peroxide system induces alpha-synuclein aggregation in vitro.
Alpha-synuclein is a key component of Lewy bodies in the brain of patients with Parkinson's disease (PD) and recent studies suggest that oxidative stress reactions might contribute to abnormal aggregation of this molecule. Since hydrogen peroxide-mediated ceruloplasmin (CP) modification can induce the formation of free radicals and release of copper ions, we investigated the role of CP in the aggregation of alpha-synuclein. When alpha-synuclein was incubated with both CP and H(2)O(2), alpha-synuclein concomitantly was induced to be aggregated. Thioflavin-S staining of alpha-synuclein aggregates showed that they displayed characteristic fibrillar structures. Hydroxyl radical scavengers and spin-trapping agent such as 5,5'-dimethyl 1-pyrolline N-oxide and tert-butyl-alpha-phenylnitrone significantly inhibited the aggregation of alpha-synuclein. Copper chelator, penicillamine also inhibited the CP/H(2)O(2) system-induced alpha-synuclein aggregation. This indicates that the aggregation of alpha-synuclein can be mediated by the CP/H(2)O(2) system via the generation of hydroxyl radical. The CP/H(2)O(2) system-induced alpha-synuclein aggregation resulted in the generation of protein carbonyl derivatives. Antioxidant molecules, carnosine, homocarnosine and anserine significantly inhibited the CP/H(2)O(2) system-induced aggregation of alpha-synuclein. These results suggest that the CP/H(2)O(2) system may be related to abnormal aggregation of alpha-synuclein which may be involved in the pathogenesis of PD and related disorders.
Kim
Kyung Sik
KS
Department of Genetic Engineering, Chongju University, Chongju 360-764, Republic of Korea.
Choi
Soo Young
SY
Kwon
Hyeok Yil
HY
Won
Moo Ho
MH
Kang
Tae-Cheon
TC
Kang
Jung Hoon
JH
D052160:Benzothiazoles; D002570:Ceruloplasmin / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry / Q000378:metabolism*; D017665:Hydroxyl Radical / Q000378:metabolism; D015151:Immunoblotting; D008854:Microscopy, Electron / Q000379:methods; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000378:metabolism*; D017510:Protein Folding; D013050:Spectrometry, Fluorescence; D013194:Staining and Labeling; D051843:Synucleins; D013844:Thiazoles / Q000737:chemistry; D051844:alpha-Synuclein
D052160:Benzothiazoles; D009419:Nerve Tissue Proteins; C497604:SNCA protein, human; D051843:Synucleins; D013844:Thiazoles; D051844:alpha-Synuclein; C009462:thioflavin T; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide; D002570:Ceruloplasmin