title: Differential S-nitrosylation of proteins in Alzheimer's disease.
abstract: Numerous studies have provided evidence regarding the involvement of protein S-nitrosylation in the progression of Alzheimer's disease (AD) pathology and its implication in the formation and accumulation of misfolded protein aggregates. The identification of S-nitrosylated proteins can be a major step toward the understanding of mechanisms leading to neuronal degeneration. The present study targeted S-nitrosylated proteins in AD hippocampus, substantia nigra and cortex using the following work-flow that combines S-nitrosothiol-specific antibody detection, classical biotin switch method labeled with fluorescence dye followed by electrospray ionization quadrupole time of flight tandem MS (ESI-QTOF MS/MS) identification. Endogenous nitrosocysteines were identified in 45 proteins, mainly involved in metabolism, signaling pathways, apoptosis and redox regulation as assigned by REACTOME and KEGG pathway database analysis. Superoxide dismutase (SOD2) [Mn], fructose-bisphosphate aldolase C (ALDOC) and voltage-dependent anion-selective channel protein 2 (VDAC2) showed differential S-nitrosylation signal, not previously reported in AD regions. Extensive neuronal atrophy with increased protein S-nitrosylation in AD regions is also evident from immunofluorescence studies using S-nitrosocysteine antibody. A number of plausible cysteine modification sites were predicted via Group-based Prediction System-S-nitrosothiols (GPS-SNO) 1.0 while STRING 8.3 analysis revealed functional annotations in the modified proteins. The findings are helpful in characterization of functional abnormalities and may facilitate the understanding of molecular mechanisms and biological function of S-nitrosylation in AD pathology.
authors.affiliation: Neurochemistry Research Laboratory, Department of Biochemistry, University of Karachi, Karachi 75270, Pakistan; Department of Clinical Chemistry, University Medical Center Goettingen, Robert-Koch-Str. 40, 37075 Goettingen, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Zahid
authors.affiliation: Neurochemistry Research Laboratory, Department of Biochemistry, University of Karachi, Karachi 75270, Pakistan.
authors.forename: R
authors.initials: R
authors.lastname: Khan
authors.affiliation: Department of Clinical Chemistry, University Medical Center Goettingen, Robert-Koch-Str. 40, 37075 Goettingen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Oellerich
authors.affiliation: Neurochemistry Research Laboratory, Department of Biochemistry, University of Karachi, Karachi 75270, Pakistan. Electronic address: nikhat_ahmed14@yahoo.co.uk.
authors.forename: N
authors.initials: N
authors.lastname: Ahmed
authors.affiliation: Department of Clinical Chemistry, University Medical Center Goettingen, Robert-Koch-Str. 40, 37075 Goettingen, Germany. Electronic address: asif@med.uni-goettingen.de.
authors.forename: A R
authors.initials: AR
authors.lastname: Asif
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000473:pathology*; D001710:Biotin / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D016022:Case-Control Studies; D003545:Cysteine / Q000031:analogs & derivatives; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism*; D006801:Humans; D008297:Male; D040901:Proteomics; D026403:S-Nitrosothiols / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism*; D053719:Tandem Mass Spectrometry; D050996:Voltage-Dependent Anion Channel 2 / Q000378:metabolism*; D000099156:Superoxide Dismutase 2
chemical_list: D001710:Biotin; D003545:Cysteine; D005634:Fructose-Bisphosphate Aldolase; D026403:S-Nitrosothiols; D013482:Superoxide Dismutase; D050996:Voltage-Dependent Anion Channel 2; D000099156:Superoxide Dismutase 2; C021315:S-nitrosocysteine
keywords: 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid; 2DE; ACT; AD; ALDO; Alzheimer’s disease; BSM; ENO; ESI-QTOF-MS/MS; GAPDH; GPS; HEPES; IP; IPG; LDH; N-ethylmaleimide; NADP; NDDs; NEM; NO; PEBP; PTMs; RNS; S-nitrosocysteine; S-nitrosothiols; SNO; SNO-Cys; SOD2; TBST; TPI; TUBA; TUBB; Tris-buffered saline and Tween 20; VDAC2; WEB-based Gene SeT AnaLysis Toolkit; WEBGESTALT; actin; aldolase; biotin switch method; cortex; electrospray ionization quadrupole time of flight tandem MS; enolase; glyceraldehyde-3-phosphate dehydrogenase; group-based prediction system; hippocampus; immobilized pH gradients; immunoprecipitation; lactate dehydrogenase; neurodegenerative diseases; nicotinamide adenine dinucleotide phosphate; nitric oxide; phosphatidylethanolamine-binding protein; post-translational modifications; protein S-nitrosylation; proteomics; reactive nitrogen species; substantia nigra; superoxide dismutase; triose phosphate isomerase; tubulin alpha; tubulin beta; two-dimensional electrophoresis; voltage-dependent anion-selective channel protein 2