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Chen Yang - One of the best experts on this subject based on the ideXlab platform.
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crystal structures and biochemical analyses of the bacterial arginine dihydrolase argz suggests a bond rotation catalytic mechanism
Journal of Biological Chemistry, 2020Co-Authors: Ningning Zhuang, Lingting Li, Xiaoxian Wu, Hao Zhang, Chen YangAbstract:: A recently discovered ornithine-ammonia cycle (OAC) serves as a conduit in the nitrogen storage-and-remobilization machinery in cyanobacteria. The OAC involves an arginine-catabolic reaction catalyzed by the arginine dihydrolase ArgZ whose catalytic mechanism is unknown. Here, we determined the crystal structures at 1.2-3.0 A of unliganded ArgZ from the cyanobacterium Synechocystis sp. PCC6803 and of ArgZ complexed with its substrate arginine, a covalently linked reaction intermediate, or the reaction product ornithine. The structures reveal that a key residue, Asn71, in the ArgZ active center, functions as the determinant distinguishing ArgZ from other members of the Guanidino Group-modifying enzyme superfamily. The structures, along with biochemical evidence from enzymatic assays coupled with electrospray ionization MS (ESI-MS) techniques, further suggest that ArgZ-catalyzed conversion of arginine to ornithine, ammonia, and carbon dioxide by ArgZ consists of two successive cycles of amine hydrolysis. Finally, we show that arginine dihydrolases are broadly distributed among bacteria and metazoan, suggesting that the OAC may be frequently used for redistribution of nitrogen from arginine catabolism or nitrogen fixation.
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crystal structures and biochemical analyses of the bacterial arginine dihydrolase argz suggests a bond rotation catalytic mechanism
Journal of Biological Chemistry, 2020Co-Authors: Ningning Zhuang, Chen Yang, Hao Zhang, Yu ZhangAbstract:A recently discovered ornithine-ammonia cycle (OAC) serves as a conduit in the nitrogen storage and remobilization machinery in cyanobacteria. The OAC involves an arginine catabolic reaction catalyzed by the arginine dihydrolase ArgZ whose catalytic mechanism is unknown. Here we determined the crystal structures at 1.2-3.0 A of unliganded ArgZ from the cyanobacterium Synechocystis sp. PCC6803 and of ArgZ complexed with its substrate arginine, a covalently linked reaction intermediate, or the reaction product ornithine. The structures reveal that a key residue, Asn71, in the ArgZ active center functions as the determinant distinguishing ArgZ from other members of the Guanidino Group-modifying enzyme superfamily. The structures, along with biochemical evidence from enzymatic assays coupled with electrospray ionization MS techniques, further suggest that ArgZ-catalyzed conversion of arginine to ornithine, ammonia, and carbon dioxide consists of two successive cycles of amine hydrolysis. Finally, we show that arginine dihydrolases are broadly distributed among bacteria and metazoans, suggesting that the OAC may be frequently used for redistribution of nitrogen from arginine catabolism or nitrogen fixation.
Ningning Zhuang - One of the best experts on this subject based on the ideXlab platform.
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crystal structures and biochemical analyses of the bacterial arginine dihydrolase argz suggests a bond rotation catalytic mechanism
Journal of Biological Chemistry, 2020Co-Authors: Ningning Zhuang, Lingting Li, Xiaoxian Wu, Hao Zhang, Chen YangAbstract:: A recently discovered ornithine-ammonia cycle (OAC) serves as a conduit in the nitrogen storage-and-remobilization machinery in cyanobacteria. The OAC involves an arginine-catabolic reaction catalyzed by the arginine dihydrolase ArgZ whose catalytic mechanism is unknown. Here, we determined the crystal structures at 1.2-3.0 A of unliganded ArgZ from the cyanobacterium Synechocystis sp. PCC6803 and of ArgZ complexed with its substrate arginine, a covalently linked reaction intermediate, or the reaction product ornithine. The structures reveal that a key residue, Asn71, in the ArgZ active center, functions as the determinant distinguishing ArgZ from other members of the Guanidino Group-modifying enzyme superfamily. The structures, along with biochemical evidence from enzymatic assays coupled with electrospray ionization MS (ESI-MS) techniques, further suggest that ArgZ-catalyzed conversion of arginine to ornithine, ammonia, and carbon dioxide by ArgZ consists of two successive cycles of amine hydrolysis. Finally, we show that arginine dihydrolases are broadly distributed among bacteria and metazoan, suggesting that the OAC may be frequently used for redistribution of nitrogen from arginine catabolism or nitrogen fixation.
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crystal structures and biochemical analyses of the bacterial arginine dihydrolase argz suggests a bond rotation catalytic mechanism
Journal of Biological Chemistry, 2020Co-Authors: Ningning Zhuang, Chen Yang, Hao Zhang, Yu ZhangAbstract:A recently discovered ornithine-ammonia cycle (OAC) serves as a conduit in the nitrogen storage and remobilization machinery in cyanobacteria. The OAC involves an arginine catabolic reaction catalyzed by the arginine dihydrolase ArgZ whose catalytic mechanism is unknown. Here we determined the crystal structures at 1.2-3.0 A of unliganded ArgZ from the cyanobacterium Synechocystis sp. PCC6803 and of ArgZ complexed with its substrate arginine, a covalently linked reaction intermediate, or the reaction product ornithine. The structures reveal that a key residue, Asn71, in the ArgZ active center functions as the determinant distinguishing ArgZ from other members of the Guanidino Group-modifying enzyme superfamily. The structures, along with biochemical evidence from enzymatic assays coupled with electrospray ionization MS techniques, further suggest that ArgZ-catalyzed conversion of arginine to ornithine, ammonia, and carbon dioxide consists of two successive cycles of amine hydrolysis. Finally, we show that arginine dihydrolases are broadly distributed among bacteria and metazoans, suggesting that the OAC may be frequently used for redistribution of nitrogen from arginine catabolism or nitrogen fixation.
Yoshifumi Takei - One of the best experts on this subject based on the ideXlab platform.
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imidazolone a novel advanced glycation end product is present at high levels in kidneys of rats with streptozotocin induced diabetes
FEBS Letters, 1997Co-Authors: Toshimitsu Niwa, Yayoi Ishizaki, Tomoyuki Katsuzaki, Noriyuki Tatemichi, Fumitaka Hayase, Takashi Miyazaki, Toshihiko Uematsu, Yoshifumi TakeiAbstract:We produced a monoclonal antibody to imidazolones A and B, novel advanced glycation end products formed from the reaction of 3-deoxyglucosone (3-DG) with the Guanidino Group of arginine. Liquid chromatography/mass spectrometry demonstrated that the formation of imidazolone A by incubating 3-DG with arginine is very rapid, reaching a maximum concentration within 24 h, but the formation of imidazolone B is very slow and low in quantity even after 2 weeks. Thus, at physiological conditions the formation of imidazolone A is dominant, while that of imidazolone B is negligible. Immunochemistry demonstrated that the imidazolone content in the kidneys of streptozotocin-induced diabetic rats was significantly higher than in the control rats. Serum levels of 3-DG in the diabetic rats were also significantly higher than in control rats. 3-DG attacks the arginine residues of the tissue proteins, producing imidazolone at high levels in the kidneys affected by diabetic nephropathy.
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Immunohistochemical detection of imidazolone, a novel advanced glycation end product, in kidneys and aortas of diabetic patients
Journal of Clinical Investigation, 1997Co-Authors: Toshimitsu Niwa, Yayoi Ishizaki, Tomoyuki Katsuzaki, Noriyuki Tatemichi, Fumitaka Hayase, Shigeru Miyazaki, Takashi Miyazaki, Yoshifumi TakeiAbstract:To investigate the role of the Maillard reaction in the pathogenesis of diabetic complications, we produced several clones of monoclonal antibodies against advanced glycation end products (AGEs) by immunizing mice with AGE-modified keyhole limpet hemocyanin, and found that one clone (AG-1) of the anti-AGE antibodies reacted specifically with imidazolones A and B, novel AGEs. Thus, the imidazolones, which are the reaction products of the Guanidino Group of arginine with 3-deoxyglucosone (3-DG), a reactive intermediate of the Maillard reaction, were found to be common epitopes of AGE-modified proteins produced in vitro. We determined the erythrocyte levels of imidazolone in diabetic patients using ELISA with the monoclonal anti-imidazolone antibody. The imidazolone levels in the erythrocytes of diabetic patients were found to be significantly increased as compared with those of healthy subjects. Then we studied the localization of imidazolone in the kidneys and aortas obtained from diabetic patients by immunohistochemistry using the antibody. Specific imidazolone immunoreactivity was detected in nodular lesions and expanded mesangial matrix of glomeruli, and renal arteries in an advanced stage of diabetic nephropathy, as well as in atherosclerotic lesions of aortas. This study first demonstrates the localization of imidazolone in the characteristic lesions of diabetic nephropathy and atherosclerosis. These results, taken together with a recent demonstration of increased serum 3-DG levels in diabetes, strongly suggest that imidazolone produced by 3-DG may contribute to the progression of long-term diabetic complications such as nephropathy and atherosclerosis.
Yu Zhang - One of the best experts on this subject based on the ideXlab platform.
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crystal structures and biochemical analyses of the bacterial arginine dihydrolase argz suggests a bond rotation catalytic mechanism
Journal of Biological Chemistry, 2020Co-Authors: Ningning Zhuang, Chen Yang, Hao Zhang, Yu ZhangAbstract:A recently discovered ornithine-ammonia cycle (OAC) serves as a conduit in the nitrogen storage and remobilization machinery in cyanobacteria. The OAC involves an arginine catabolic reaction catalyzed by the arginine dihydrolase ArgZ whose catalytic mechanism is unknown. Here we determined the crystal structures at 1.2-3.0 A of unliganded ArgZ from the cyanobacterium Synechocystis sp. PCC6803 and of ArgZ complexed with its substrate arginine, a covalently linked reaction intermediate, or the reaction product ornithine. The structures reveal that a key residue, Asn71, in the ArgZ active center functions as the determinant distinguishing ArgZ from other members of the Guanidino Group-modifying enzyme superfamily. The structures, along with biochemical evidence from enzymatic assays coupled with electrospray ionization MS techniques, further suggest that ArgZ-catalyzed conversion of arginine to ornithine, ammonia, and carbon dioxide consists of two successive cycles of amine hydrolysis. Finally, we show that arginine dihydrolases are broadly distributed among bacteria and metazoans, suggesting that the OAC may be frequently used for redistribution of nitrogen from arginine catabolism or nitrogen fixation.
Hao Zhang - One of the best experts on this subject based on the ideXlab platform.
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crystal structures and biochemical analyses of the bacterial arginine dihydrolase argz suggests a bond rotation catalytic mechanism
Journal of Biological Chemistry, 2020Co-Authors: Ningning Zhuang, Lingting Li, Xiaoxian Wu, Hao Zhang, Chen YangAbstract:: A recently discovered ornithine-ammonia cycle (OAC) serves as a conduit in the nitrogen storage-and-remobilization machinery in cyanobacteria. The OAC involves an arginine-catabolic reaction catalyzed by the arginine dihydrolase ArgZ whose catalytic mechanism is unknown. Here, we determined the crystal structures at 1.2-3.0 A of unliganded ArgZ from the cyanobacterium Synechocystis sp. PCC6803 and of ArgZ complexed with its substrate arginine, a covalently linked reaction intermediate, or the reaction product ornithine. The structures reveal that a key residue, Asn71, in the ArgZ active center, functions as the determinant distinguishing ArgZ from other members of the Guanidino Group-modifying enzyme superfamily. The structures, along with biochemical evidence from enzymatic assays coupled with electrospray ionization MS (ESI-MS) techniques, further suggest that ArgZ-catalyzed conversion of arginine to ornithine, ammonia, and carbon dioxide by ArgZ consists of two successive cycles of amine hydrolysis. Finally, we show that arginine dihydrolases are broadly distributed among bacteria and metazoan, suggesting that the OAC may be frequently used for redistribution of nitrogen from arginine catabolism or nitrogen fixation.
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crystal structures and biochemical analyses of the bacterial arginine dihydrolase argz suggests a bond rotation catalytic mechanism
Journal of Biological Chemistry, 2020Co-Authors: Ningning Zhuang, Chen Yang, Hao Zhang, Yu ZhangAbstract:A recently discovered ornithine-ammonia cycle (OAC) serves as a conduit in the nitrogen storage and remobilization machinery in cyanobacteria. The OAC involves an arginine catabolic reaction catalyzed by the arginine dihydrolase ArgZ whose catalytic mechanism is unknown. Here we determined the crystal structures at 1.2-3.0 A of unliganded ArgZ from the cyanobacterium Synechocystis sp. PCC6803 and of ArgZ complexed with its substrate arginine, a covalently linked reaction intermediate, or the reaction product ornithine. The structures reveal that a key residue, Asn71, in the ArgZ active center functions as the determinant distinguishing ArgZ from other members of the Guanidino Group-modifying enzyme superfamily. The structures, along with biochemical evidence from enzymatic assays coupled with electrospray ionization MS techniques, further suggest that ArgZ-catalyzed conversion of arginine to ornithine, ammonia, and carbon dioxide consists of two successive cycles of amine hydrolysis. Finally, we show that arginine dihydrolases are broadly distributed among bacteria and metazoans, suggesting that the OAC may be frequently used for redistribution of nitrogen from arginine catabolism or nitrogen fixation.
