title: In vivo protein targets for increased quinoprotein adduct formation in aged substantia nigra.
abstract: The selective vulnerability of dopaminergic neurons in the substantia nigra pars compacta in Parkinson's disease, a late age onset neurodegenerative disorder, indicates the involvement of dopamine metabolism in the pathogenesis. Dopamine oxidation produces dopamine o-quinone, which covalently modifies cysteinyl proteins forming quinoprotein adduct. Although quinoprotein formation correlates with increased dopaminergic neurotoxicity, the in vivo protein targets for quinone modification remain unclear. Using two-dimensional gel electrophoresis and nitroblue tetrazolium/glycinate redox-cycling staining, we compared quinoprotein adducts in the substantia nigra of 2- and 15-month old rats and for the first time identified the in vivo protein targets with increased quinone modification in aged substantia nigra. Interestingly, several key enzymes in energy metabolism and mitochondrial function were selectively modified by quinone during aging. In vitro analyses confirmed that two of identified enzymes, l-lactate dehydrogenase (LDH) and malate dehydrogenase (MDH), were readily conjugated by dopamine o-quinone, resulting in a significant reduction in enzyme activity. Since the proteomic approach to detect quinoprotein adducts represents a single analysis comparing pools of substantia nigra from young or old rats, these findings need to be verified in the future. Nonetheless, our results reveal that the enzymatic activity of LDH and MDH can be compromised by quinone modification, suggesting a role of energy metabolism impairment in the selective vulnerability of aged substantia nigra dopaminergic neurons in Parkinson's disease.
authors.affiliation: Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, Shanghai, China. Electronic address: xiaoqsh2003@163.com.
authors.forename: Guohua
authors.initials: G
authors.lastname: Yu
authors.affiliation: Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, Shanghai, China.
authors.forename: Huiyan
authors.initials: H
authors.lastname: Liu
authors.affiliation: Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, Shanghai, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, Shanghai, China.
authors.forename: Xuewei
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, Shanghai, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Yu
authors.affiliation: Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, Shanghai, China.
authors.forename: Na
authors.initials: N
authors.lastname: Wang
authors.affiliation: Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, Shanghai, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, Shanghai, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Ma
authors.affiliation: Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, Shanghai, China.
authors.forename: Yulan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, Shanghai, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, East China Normal University, Shanghai, China.
authors.forename: Lujian
authors.initials: L
authors.lastname: Liao
authors.affiliation: Shandong Provincial Research Center for Bioinformatic Engineering and Technique, Center for Advanced Study, Shandong University of Technology, Zibo, China.
authors.forename: Hongfang
authors.initials: H
authors.lastname: Ji
authors.affiliation: Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, Shanghai, China.
authors.forename: Chonggang
authors.initials: C
authors.lastname: Yuan
authors.affiliation: Key Laboratory of Brain Functional Genomics (East China Normal University), Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), School of Life Sciences, East China Normal University, Shanghai, China; Center for Neurodegenerative Science, Van Andel Research Institute, Grand Rapids, MI, USA. Electronic address: jiyan.ma@vai.org.
authors.forename: Jiyan
authors.initials: J
authors.lastname: Ma
mesh_terms: D000367:Age Factors; D000375:Aging; D000818:Animals; D016227:Benzoquinones / Q000378:metabolism / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004298:Dopamine / Q000031:analogs & derivatives / Q000494:pharmacology; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000378:metabolism; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009447:Neuroblastoma / Q000473:pathology; D009580:Nitroblue Tetrazolium / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013378:Substantia Nigra / Q000187:drug effects* / Q000378:metabolism*; D013997:Time Factors
chemical_list: D016227:Benzoquinones; D009419:Nerve Tissue Proteins; D011506:Proteins; D009580:Nitroblue Tetrazolium; C027262:DAQ; C104705:dopamine quinone; D007770:L-Lactate Dehydrogenase; D008291:Malate Dehydrogenase; D004298:Dopamine
keywords: Dopamine quinone; Energy metabolism; Parkinson's disease; Quinoprotein; Substantia nigra