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Lian-hui Zhang - One of the best experts on this subject based on the ideXlab platform.
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Succinic Semialdehyde promotes prosurvival capability of agrobacterium tumefaciens
Journal of Bacteriology, 2016Co-Authors: Chao Wang, Desong Tang, Yonggui Gao, Lian-hui ZhangAbstract:ABSTRACT Succinic Semialdehyde (SSA), an important metabolite of γ-aminobutyric acid (GABA), is a ligand of the repressor AttJ regulating the expression of the attJ-attKLM gene cluster in the plant pathogen Agrobacterium tumefaciens. While the response of A. tumefaciens to GABA and the function of attKLM have been extensively studied, genetic and physiological responses of A. tumefaciens to SSA remain unknown. In combination with microarray and genetic approaches, this study sets out to explore new roles of the SSA-AttJKLM regulatory mechanism during bacterial infection. The results showed that SSA plays a key role in regulation of several bacterial activities, including C4-dicarboxylate utilization, nitrate assimilation, and resistance to oxidative stress. Interestingly, while the SSA relies heavily on the functional AttKLM in mediating nitrate assimilation and oxidative stress resistance, the compound could regulate utilization of C4-dicarboxylates independent of AttJKLM. We further provide evidence that SSA controls C4-dicarboxylate utilization through induction of an SSA importer and that disruption of attKLM attenuates the tumorigenicity of A. tumefaciens. Taken together, these findings indicate that SSA could be a potent plant signal which, together with AttKLM, plays a vital role in promoting the bacterial prosurvival abilities during infection. IMPORTANCEAgrobacterium tumefaciens is a plant pathogen causing crown gall diseases and has been well known as a powerful tool for plant genetic engineering. During the long history of microbe-host interaction, A. tumefaciens has evolved the capabilities of recognition and response to plant-derived chemical metabolites. Succinic Semialdehyde (SSA) is one such metabolite. Previous results have demonstrated that SSA functions to activate a quorum-quenching mechanism and thus to decrease the level of quorum-sensing signals, thereby avoiding the elicitation of a plant defense. Here, we studied the effect of SSA on gene expression at a genome-wide level and reported that SSA also promotes bacterial survival during infection. These findings provide a new insight on the biological significance of chemical signaling between agrobacteria and plant hosts.
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Succinic Semialdehyde couples stress response to quorum sensing signal decay in agrobacterium tumefaciens
Molecular Microbiology, 2006Co-Authors: Chao Wang, Hai-bao Zhang, Lian-hui Wang, Lian-hui ZhangAbstract:Summary Quorum sensing (QS) signal decay in Agrobacterium tumefaciens occurs in response to starvation or host signals. We have demonstrated that the γ-aminobutyric acid (GABA) shunt metabolite links stress response to QS signal decay. Mutation of the aldH gene encoding a Succinic Semialdehyde dehydrogenase (SSADH) that converts Succinic Semialdehyde (SSA) to Succinic acid results in early expression of the signal degrading enzyme, AttM. Exogenous addition of SSA or its precursor GABA induces AttM expression and abolishes Ti plasmid conjugative transfer. SSA acts by binding to the repressor AttJ that regulates the attKLM operon. attK encodes another SSADH. The stress alarmone ppGpp and SSA modulates separately the expression of the two SSADH enzymes, which might control the intracellular SSA level and hence to switch on/off the QS signal decay system in response to environmental changes. These findings document for the first time a sophisticated signalling mechanism of the widely conserved GABA degradation pathway in prokaryotes.
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Succinic Semialdehyde couples stress response to quorum‐sensing signal decay in Agrobacterium tumefaciens
Molecular microbiology, 2006Co-Authors: Chao Wang, Hai-bao Zhang, Lian-hui Wang, Lian-hui ZhangAbstract:Summary Quorum sensing (QS) signal decay in Agrobacterium tumefaciens occurs in response to starvation or host signals. We have demonstrated that the γ-aminobutyric acid (GABA) shunt metabolite links stress response to QS signal decay. Mutation of the aldH gene encoding a Succinic Semialdehyde dehydrogenase (SSADH) that converts Succinic Semialdehyde (SSA) to Succinic acid results in early expression of the signal degrading enzyme, AttM. Exogenous addition of SSA or its precursor GABA induces AttM expression and abolishes Ti plasmid conjugative transfer. SSA acts by binding to the repressor AttJ that regulates the attKLM operon. attK encodes another SSADH. The stress alarmone ppGpp and SSA modulates separately the expression of the two SSADH enzymes, which might control the intracellular SSA level and hence to switch on/off the QS signal decay system in response to environmental changes. These findings document for the first time a sophisticated signalling mechanism of the widely conserved GABA degradation pathway in prokaryotes.
Chao Wang - One of the best experts on this subject based on the ideXlab platform.
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Succinic Semialdehyde promotes prosurvival capability of agrobacterium tumefaciens
Journal of Bacteriology, 2016Co-Authors: Chao Wang, Desong Tang, Yonggui Gao, Lian-hui ZhangAbstract:ABSTRACT Succinic Semialdehyde (SSA), an important metabolite of γ-aminobutyric acid (GABA), is a ligand of the repressor AttJ regulating the expression of the attJ-attKLM gene cluster in the plant pathogen Agrobacterium tumefaciens. While the response of A. tumefaciens to GABA and the function of attKLM have been extensively studied, genetic and physiological responses of A. tumefaciens to SSA remain unknown. In combination with microarray and genetic approaches, this study sets out to explore new roles of the SSA-AttJKLM regulatory mechanism during bacterial infection. The results showed that SSA plays a key role in regulation of several bacterial activities, including C4-dicarboxylate utilization, nitrate assimilation, and resistance to oxidative stress. Interestingly, while the SSA relies heavily on the functional AttKLM in mediating nitrate assimilation and oxidative stress resistance, the compound could regulate utilization of C4-dicarboxylates independent of AttJKLM. We further provide evidence that SSA controls C4-dicarboxylate utilization through induction of an SSA importer and that disruption of attKLM attenuates the tumorigenicity of A. tumefaciens. Taken together, these findings indicate that SSA could be a potent plant signal which, together with AttKLM, plays a vital role in promoting the bacterial prosurvival abilities during infection. IMPORTANCEAgrobacterium tumefaciens is a plant pathogen causing crown gall diseases and has been well known as a powerful tool for plant genetic engineering. During the long history of microbe-host interaction, A. tumefaciens has evolved the capabilities of recognition and response to plant-derived chemical metabolites. Succinic Semialdehyde (SSA) is one such metabolite. Previous results have demonstrated that SSA functions to activate a quorum-quenching mechanism and thus to decrease the level of quorum-sensing signals, thereby avoiding the elicitation of a plant defense. Here, we studied the effect of SSA on gene expression at a genome-wide level and reported that SSA also promotes bacterial survival during infection. These findings provide a new insight on the biological significance of chemical signaling between agrobacteria and plant hosts.
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Succinic Semialdehyde couples stress response to quorum sensing signal decay in agrobacterium tumefaciens
Molecular Microbiology, 2006Co-Authors: Chao Wang, Hai-bao Zhang, Lian-hui Wang, Lian-hui ZhangAbstract:Summary Quorum sensing (QS) signal decay in Agrobacterium tumefaciens occurs in response to starvation or host signals. We have demonstrated that the γ-aminobutyric acid (GABA) shunt metabolite links stress response to QS signal decay. Mutation of the aldH gene encoding a Succinic Semialdehyde dehydrogenase (SSADH) that converts Succinic Semialdehyde (SSA) to Succinic acid results in early expression of the signal degrading enzyme, AttM. Exogenous addition of SSA or its precursor GABA induces AttM expression and abolishes Ti plasmid conjugative transfer. SSA acts by binding to the repressor AttJ that regulates the attKLM operon. attK encodes another SSADH. The stress alarmone ppGpp and SSA modulates separately the expression of the two SSADH enzymes, which might control the intracellular SSA level and hence to switch on/off the QS signal decay system in response to environmental changes. These findings document for the first time a sophisticated signalling mechanism of the widely conserved GABA degradation pathway in prokaryotes.
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Succinic Semialdehyde couples stress response to quorum‐sensing signal decay in Agrobacterium tumefaciens
Molecular microbiology, 2006Co-Authors: Chao Wang, Hai-bao Zhang, Lian-hui Wang, Lian-hui ZhangAbstract:Summary Quorum sensing (QS) signal decay in Agrobacterium tumefaciens occurs in response to starvation or host signals. We have demonstrated that the γ-aminobutyric acid (GABA) shunt metabolite links stress response to QS signal decay. Mutation of the aldH gene encoding a Succinic Semialdehyde dehydrogenase (SSADH) that converts Succinic Semialdehyde (SSA) to Succinic acid results in early expression of the signal degrading enzyme, AttM. Exogenous addition of SSA or its precursor GABA induces AttM expression and abolishes Ti plasmid conjugative transfer. SSA acts by binding to the repressor AttJ that regulates the attKLM operon. attK encodes another SSADH. The stress alarmone ppGpp and SSA modulates separately the expression of the two SSADH enzymes, which might control the intracellular SSA level and hence to switch on/off the QS signal decay system in response to environmental changes. These findings document for the first time a sophisticated signalling mechanism of the widely conserved GABA degradation pathway in prokaryotes.
K. Michael Gibson - One of the best experts on this subject based on the ideXlab platform.
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Gamma-Hydroxybutyrate content in dried bloodspots facilitates newborn detection of Succinic Semialdehyde dehydrogenase deficiency.
Molecular genetics and metabolism, 2019Co-Authors: Madalyn Brown, Paula Ashcraft, Erland Arning, Teodoro Bottiglieri, Jean-baptiste Roullet, K. Michael GibsonAbstract:Abstract Increased gamma-hydroxybutyric acid in urine and blood are metabolic hallmarks of Succinic Semialdehyde dehydrogenase deficiency, a defect of 4-aminobutyric acid metabolism. Here, we examined the hypothesis that Succinic Semialdehyde dehydrogenase deficiency could be identified via measurement of gamma-hydroxybutyric acid in newborn and post-newborn dried bloodspots. Quantitation of gamma-hydroxybutyric acid using liquid chromatography-tandem mass spectrometry in twelve archival newborn patient dried bloodspots was 360 ± 57 μM (mean, standard error; range 111–767), all values exceeding the previously established cutoff for newborn detection of 78 μΜ established from 2831 dried bloodspots derived from newborns, neonates and children. Gamma-hydroxybutyric acid in post-newborn dried bloodspots (n = 19; ages 0.8–38 years) was 191 ± 65 μM (mean, standard error; range 20–1218), exceeding the aforementioned GHB cutoff for patients approximately 10 years of age or younger. Further, gamma-hydroxybutyric acid in post-newborn dried bloodspots displayed a significant (p
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Biomarkers in a Taurine Trial for Succinic Semialdehyde Dehydrogenase Deficiency.
JIMD reports, 2016Co-Authors: John M. Schreiber, K. Michael Gibson, Phillip L. Pearl, Irene Dustin, Edythe Wiggs, Emily Barrios, Eric M. Wassermann, William H. TheodoreAbstract:Aim: We tested the hypothesis that patients with Succinic Semialdehyde dehydrogenase (SSADH) deficiency on taurine would have decreased cortical excitability as measured by transcranial magnetic stimulation (TMS) and improved cognition, due to taurine’s partial GABA(A and B) receptor agonist effects and rescue in the null mouse model from status epilepticus and premature lethality.
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Therapeutic efficacy of magnesium valproate in Succinic Semialdehyde dehydrogenase deficiency.
JIMD reports, 2012Co-Authors: Elena Vanadia, K. Michael Gibson, Phillip L. Pearl, Emanuele Trapolino, Salvatore Mangano, Francesca VanadiaAbstract:Succinic Semialdehyde dehydrogenase deficiency (SSADHD), a disorder of γ-aminobutyric acid (GABA) metabolism, manifests typically as a nonprogressive neurodevelopmental disorder with cognitive deficiency, neuropsychiatric morbidity and epilepsy. Therapy targets symptomatic seizures and neurobehavioral disturbances. We report an adolescent female with SSADHD whose unresponsiveness to a broad spectrum of antiepileptics was circumvented with magnesium valproate (MgVPA). Epilepsy remains well controlled in our patient, with concomitant improvements in behavioral symptoms and an absence of adverse symptoms. MgVPA intervention may have utility in SSADHD.
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Epilepsy in Succinic Semialdehyde dehydrogenase deficiency, a disorder of GABA metabolism
Brain & development, 2011Co-Authors: Phillip L. Pearl, Cornelis Jakobs, Lovy Shukla, William H. Theodore, K. Michael GibsonAbstract:Objectives Succinic Semialdehyde dehydrogenase (SSADH) deficiency is a gamma-aminobutyric acid (GABA) degradative defect. Epilepsy affects half of patients. The murine model is associated with a transition from absence to convulsive seizures in the third week, with fatal status epilepticus.
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Neuropathology in Succinic Semialdehyde dehydrogenase deficiency.
Pediatric neurology, 2010Co-Authors: Ina Knerr, K. Michael Gibson, Geoffrey Murdoch, Gajja S. Salomons, Cornelis Jakobs, Susan E. Combs, Phillip L. PearlAbstract:Reported here is the novel finding of neuropathology in a patient with Succinic Semialdehyde dehydrogenase deficiency, an inherited disorder of γ-aminobutyric acid metabolism characterized by intellectual deficiency, hypotonia, and epilepsy, with 4-hydroxybutyric aciduria and abnormalities of the globus pallidus on neuroimaging. A 19-year-old woman of European origin with a neurodevelopmental disorder and epilepsy died unexpectedly in 1998. A postmortem examination was performed, with a final diagnosis of sudden unexpected death in epilepsy patients. Eight years later, her sister with a neurodevelopmental disorder presented at 13 years of age with seizures and was diagnosed with Succinic Semialdehyde dehydrogenase deficiency. In the decedent, Succinic Semialdehyde dehydrogenase deficiency was established at the molecular level, 10 years after her death, using genomic DNA from brain tissue specimens. The neuropathologic findings revealed striking discoloration of the globi pallidi, leptomeningeal congestion, and a scar in the frontal cortex. After detection of the pathogenic homozygous mutation c.1226G>A, p.Gly409Asp in the living sister, it was confirmed in the decedent. An underlying metabolic disease may be an additional risk factor for sudden unexpected death in epilepsy patients.
Matthew J. Picklo - One of the best experts on this subject based on the ideXlab platform.
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The conserved R166 residue of ALDH5A (Succinic Semialdehyde dehydrogenase) has multiple functional roles.
Chemico-biological interactions, 2008Co-Authors: Nathan P Swenby, Matthew J. PickloAbstract:ALDH5 (aka Succinic Semialdehyde dehydrogenase) is a NAD(+)-dependent aldehyde dehydrogenase crucial for the proper removal of the GABA metabolite Succinic Semialdehyde (SSA). All known ALDH5 family members contain the conserved amino acid sequence "MITRK". Our studies of rat ALDH5A indicate that residue R166 in this sequence may play a role in the substrate specificity of ALDH5A for the gamma-carboxylated Succinic Semialdehyde versus other aliphatic and aromatic aldehydes including acetaldehyde and benzaldehyde. We tested the hypothesis that the R166 residue regulates aldehyde specificity by utilizing rat ALDH5A wild-type (R166wt) and R166K, R166H, R166A, and R166E mutants. The V(MAX) using SSA fell whereas the K(M) for SSA increased for all mutants analyzed yielding k(cat)/K(M) (s(-1)/microM) ratios of 52.3 (R166wt), 5.5 (R166K), 0.01 (R166H), 0.008 (R166E), and 0.004 (R166A). Utilization of acetaldehyde by the R166H mutant was similar to R166wt with k(cat)/K(M)'s of 0.003 and 0.002, respectively. Almost no activity towards acetaldehyde was noted for the R166E and R166A mutants. Unexpectedly, the K(M) for NAD(+) changed: 21 microM (R166wt), 81 microM (R166K), 63 microM (R166H), 35 microM (R166E) and 44 microM (R166A). As release of NADH can be a rate-limiting step for ALDH activity, NADH binding was evaluated for R166wt and R166H enzymes. The K(D) of NADH for R166H (0.9 microM) was 11-fold less than that of ALDH5A wt (10.3 microM) and possibly explains the increase in the K(M) for NAD(+). Furthermore, data using R166K and R166H mutants demonstrate that inhibition of enzyme activity by low pH is regulated in part by the R166 residue. Our data indicate that the R166 residue of ALDH5A regulates multiple enzymatic functions.
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oxidation of 4 hydroxy 2 nonenal by Succinic Semialdehyde dehydrogenase aldh5a
Journal of Neurochemistry, 2004Co-Authors: Tonya C. Murphy, Michael K Gibson, Venkataraman Amarnath, Matthew J. PickloAbstract:Elevated levels of 4-hydroxy-trans-2-nonenal (HNE) are implicated in the pathogenesis of numerous neurodegenerative disorders. Although well-characterized in the periphery, the mechanisms of detoxification of HNE in the CNS are unclear. HNE is oxidized to a non-toxic metabolite in the rat cerebral cortex by mitochondrial aldehyde dehydrogenases (ALDHs). Two possible ALDH enzymes which might oxidize HNE in CNS mitochondria are ALDH2 and Succinic Semialdehyde dehydrogenase (SSADH/ALDH5A). It was previously established that hepatic ALDH2 can oxidize HNE. In this work, we tested the hypothesis that SSADH oxidizes HNE. SSADH is critical in the detoxification of the GABA metabolite, Succinic Semialdehyde (SSA). Recombinant rat SSADH oxidized HNE and other α,β-unsaturated aldehydes. Inhibition and competition studies in rat brain mitochondria showed that SSADH was the predominant oxidizing enzyme for HNE but only contributed a portion of the total oxidizing activity in liver mitochondria. In vivo administration of diethyldithiocarbamate (DEDC) effectively inhibited (86%) ALDH2 activity but not HNE oxidation in liver mitochondria. The data suggest that a relationship between the detoxification of SSA and the neurotoxic aldehyde HNE exists in the CNS. Furthermore, these studies show that multiple hepatic aldehyde dehydrogenases are able to oxidize HNE.
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Oxidation of 4‐hydroxy‐2‐nonenal by Succinic Semialdehyde dehydrogenase (ALDH5A)
Journal of neurochemistry, 2004Co-Authors: Tonya C. Murphy, K. Michael Gibson, Venkataraman Amarnath, Matthew J. PickloAbstract:Elevated levels of 4-hydroxy-trans-2-nonenal (HNE) are implicated in the pathogenesis of numerous neurodegenerative disorders. Although well-characterized in the periphery, the mechanisms of detoxification of HNE in the CNS are unclear. HNE is oxidized to a non-toxic metabolite in the rat cerebral cortex by mitochondrial aldehyde dehydrogenases (ALDHs). Two possible ALDH enzymes which might oxidize HNE in CNS mitochondria are ALDH2 and Succinic Semialdehyde dehydrogenase (SSADH/ALDH5A). It was previously established that hepatic ALDH2 can oxidize HNE. In this work, we tested the hypothesis that SSADH oxidizes HNE. SSADH is critical in the detoxification of the GABA metabolite, Succinic Semialdehyde (SSA). Recombinant rat SSADH oxidized HNE and other α,β-unsaturated aldehydes. Inhibition and competition studies in rat brain mitochondria showed that SSADH was the predominant oxidizing enzyme for HNE but only contributed a portion of the total oxidizing activity in liver mitochondria. In vivo administration of diethyldithiocarbamate (DEDC) effectively inhibited (86%) ALDH2 activity but not HNE oxidation in liver mitochondria. The data suggest that a relationship between the detoxification of SSA and the neurotoxic aldehyde HNE exists in the CNS. Furthermore, these studies show that multiple hepatic aldehyde dehydrogenases are able to oxidize HNE.
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Inhibition of Succinic Semialdehyde dehydrogenase activity by alkenal products of lipid peroxidation.
Biochimica et biophysica acta, 2003Co-Authors: Ethan Nguyen, Matthew J. PickloAbstract:Abstract Lipid peroxidation causes the generation of the neurotoxic aldehydes acrolein and 4-hydroxy- trans -2-nonenal (HNE). These products are elevated in neurodegenerative diseases and acute CNS trauma. Previous studies demonstrate that mitochondrial class 2 aldehyde dehydrogenase (ALDH2) is susceptible to inactivation by these alkenals. In the liver and brain another mitochondrial aldehyde dehydrogenase, Succinic Semialdehyde dehydrogenase (SSADH/ALDH5A1), is present. In this study, we tested the hypothesis that aldehyde products of lipid peroxidation inhibit SSADH activity using the endogenous substrate, Succinic Semialdehyde (SSA, 50 μM). Acrolein potently inhibited SSADH activity (IC 50 =15 μM) in rat brain mitochondrial preparations. This inhibition was of an irreversible and noncompetitive nature. HNE inhibited activity with an IC 50 of 110 μM. Trans -2-hexenal (HEX) and crotonaldehyde (100 μM each) did not inhibit activity. These data suggest that acrolein and HNE disrupt SSA metabolism and may have subsequent effects on CNS neurochemistry.
Soo Young Choi - One of the best experts on this subject based on the ideXlab platform.
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Brain Succinic Semialdehyde dehydrogenase: identification of reactive lysyl residues labeled with pyridoxal-5′-phosphate
Journal of neurochemistry, 2008Co-Authors: Soo Young Choi, Jae Hoon Bahn, Byung Ryong Lee, Seong Gyu Jeon, Joong Sik Jang, Choong Kwon Kim, Li Hua Jin, Kyunghee Kim, Jin Sun Park, Jinseu ParkAbstract:An NAD+ dependent Succinic Semialdehyde dehydrogenase from bovine brain was inactivated by pyridoxal-5'- phosphate. Spectral evidence is presented to indicate that the inactivation proceeds through formation of a Schiff's base with amino groups of the enzyme. After NaBH(4) reduction of the pyridoxal-5'-phosphate inactivated enzyme, it was observed that 3.8 mol phosphopyridoxyl residues were incorporated/enzyme tetramer. The coenzyme, NAD+, protected the enzyme against inactivation by pyridoxal-5'-phosphate. The absorption spectrum of the reduced and dialyzed pyridoxal-5'-phosphate-inactivated enzyme showed a characteristic peak at 325 nm, which was absent in the spectrum of the native enzyme. The fluorescence spectrum of the pyridoxyl enzyme differs completely from that of the native enzyme. After tryptic digestion of the enzyme modified with pyridoxal-5'-phosphate followed by [3H]NaBH4 reduction, a radioactive peptide absorbing at 210 nm was isolated by reverse-phase HPLC. The sequences of the peptide containing the phosphopyridoxyllysine were clearly identical to sequences of other mammalian Succinic Semialdehyde dehydrogenase brain species including human. It is suggested that the catalytic function of Succinic Semialdehyde dehydrogenase is modulated by binding of pyridoxal-5'-phosphate to specific Lys(347) residue at or near the coenzyme-binding site of the protein.
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Production and Characterization of Monoclonal Antibodies to Bovine Brain Succinic Semialdehyde Reductase
Journal of neurochemistry, 2002Co-Authors: Eui Yul Choi, Sang Ho Jang, Sung-woo Cho, Sang Yeol Park, Min-sun Song, Soo Young ChoiAbstract:: Monoclonal antibodies against bovine brain Succinic Semialdehyde reductase were produced and characterized. A total of nine monoclonal antibodies recognizing different epitopes of the enzyme were obtained, of which two inhibited the enzyme activity and three stained cytosol of rat spinal cord neurons as observed by indirect immunofluorescence microscopy. When unfractionated total proteins of bovine brain homogenate were separated by gel electrophoresis and immunoblotted, the antibodies specifically recognized a single protein band of 34 kDa, which comigrates with purified bovine Succinic Semialdehyde reductase. Using the antiSuccinic Semialdehyde reductase antibodies as probes, we investigated the cross-reactivities of brain Succinic Semialdehyde reductases from some mammalian and an avian species. The immunoreactive bands on western blots appeared to be the same in molecular mass—34 kDa—in all animal species tested, including humans. The result indicates that brain Succinic Semialdehyde reductase is distinct from other aldehyde reductases and that mammalian brains contain only one Succinic Semialdehyde reductase. Moreover, the enzymes among the species are immunologically very similar, although some properties of the enzymes reported previously were different from one another.
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Chemical Modification of Bovine Brain Succinic Semialdehyde Reductase by Diethylpyrocarbonate
Journal of Biochemistry and Molecular Biology, 1999Co-Authors: Byung Ryong Lee, Jae Hoon Bahn, Seong Gyu Jeon, Sung-woo Cho, Kyung-soon Choi, Byung-hak Yoon, Yoon-kyung Ahn, Eun-a Choi, Kil-soo Lee, Soo Young ChoiAbstract:The NADPH-dependent Succinic Semialdehyde reductase is one of the key enzymes in the brain GABA shunt, and it catalyzes the formation of the neuromodulator -hydroxybutyrate from Succinic semi aldehyde. This enzyme was inactivated by diethylpyrocarbonate (DEP) with the second-order rate constant of at pH 7.0, , showing a concomitant increase in absorbance at 242 nm due to the formation of N-carbethoxyhistidyl derivatives. Complete inactivation of Succinic Semialdehyde reductase required the modification of five histidyl residues per molecule of enzyme. However, only one residue was calculated to be essential for enzyme activity by a statistical analysis of the residual enzyme activity. The inactivation of the enzyme by DEP was prevented by preincubation of the enzyme with the coenzyme NADPH but not with the substrate Succinic Semialdehyde. These results suggest that an essential histidyl residue involved in the catalytic activity is located at or near the coenzyme binding site of the brain Succinic Semialdehyde reductase.
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Isolation and identification of Succinic Semialdehyde dehydrogenase inhibitory compound from the rhizome ofGastrodia elata blume
Archives of pharmacal research, 1999Co-Authors: Nam-in Baek, Soo Young Choi, Jae Hoon Bahn, Byung Ryong Lee, Seong Gyu Jeon, Sung-woo Cho, Jin Kyu Park, Eun-mi Ahn, Yong Kyu Kim, Il Hwan ShonAbstract:In our search for the anticonvulsant constituent ofGastrodia elata repeated column chromatographies guided by activity assay led to isolation of an active compound, which was identified as gastrodin on the basis of spectral data. Brain Succinic Semialdehyde dehydrogenase (SSADH) was inactivated by preincubation with gastrodin in a time-dependent manner and the reaction was monitored by absorption and fluorescence spectroscopic methods. The inactivation followed pseudo-first-order kinetics with the second-rate order constant of 1.2×103 M−1 min−1. The time course of the reaction was significantly affected by the coenzyme NAD+, which affected complete protection against the loss of the catalytic activity, whereas substrate Succinic Semialdehyde failed to prevent the inactivation of the enzyme. It is postulated that the gastrodin is able to elevate the neurotransmitter GABA levels in central nervous system by inhibitory action on one of the GABA degradative enzymes, SSADH.
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Distribution of Succinic Semialdehyde reductase in rat brain.
Molecules and cells, 1997Co-Authors: Jong Eun Lee, Soo Young Choi, Jae Wook Suk, Joung-woo Hong, Byung Kwon Yoo, Eui Yul Choi, Sang Ho Jang, Kyung Ah Park, Sung-woo ChoAbstract:Succinic Semialdehyde reductase (SSR) that catalyzes the reduction of Succinic Semialdehyde (SSA) to gamma-hydroxybutyrate (GHB) has been identified as one of the NADPH-dependent aldehyde reductases. Reduction of SSA to GHB strongly supports the proposal that GHB biosynthesis may be an important step in the GABA shunt. It is pharmacologically significant in anesthesia, evoking the state of sleep, and an increase in brain dopamine level. Monoclonal antibodies against bovine brain Succinic Semialdehyde reductase were produced. Using the anti-Succinic Semialdehyde reductase antibodies, we investigated the distribution of brain Succinic Semialdehyde reductase in rat brain. The brain tissues were sectioned with a basis on the rat brain atlas of Paxinos and were stained by the immunoperoxidase staining method using monoclonal antibodies. In the section of the frontal lobe, immunoreactive cells were observed in the lateral septal area, the ventral pallidum, which belongs to the substantia innominata. We could observe immunoreactive cells in the reticular thalamic nucleus, which is closely related with 'sleeping', the basal nuclei of Meynert, which is associated with Alzheimer's disease, and hypothalamic nuclei. Immunoreactive cells were also shown in raphe nuclei or the reticular formation of the midbrain, cerebellum, and inferior olivary nuclei of the medulla oblongata. Succinic Semialdehyde reductase-immunoreactive cells were distributed extensively in rat brain, especially immunoreactive cells were strongly observed in the areas associated with the limbic system and reticular formation.
