The Experts below are selected from a list of 225 Experts worldwide ranked by ideXlab platform
Petr Galuszka - One of the best experts on this subject based on the ideXlab platform.
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Purification of Maize Nucleotide Pyrophosphatase/Phosphodiesterase Casts Doubt on the Existence of Zeatin Cis-Trans Isomerase in Plants.
Frontiers in Plant Science, 2017Co-Authors: Tomas Hluska, Marek Sebela, Rene Lenobel, Ivo Frebort, Petr GaluszkaAbstract:Almost 25 years ago, an enzyme named zeatin cis trans isomerase from common bean has been described by Bassil et al. in Plant Physiol. (1993) 102: 867-872. The partially purified enzyme required an external addition of FAD and dithiothreitol for the conversion of cis-zeatin to its trans- isomer that occurred only under light. Although an existence of this important enzyme involved in the metabolism of plant hormones cytokinins was generally accepted by plant biologists, the corresponding protein and encoding gene have not been identified to date. Based on the original paper, we purified and identified an enzyme from maize, which shows the described zeatin cis trans isomerase activity. The enzyme belongs to Nucleotide Pyrophosphatase/phosphodiesterase family, which is well characterized in mammals, but less known in plants. Further experiments with the recombinant maize enzyme obtained from yeast expression system showed that rather than the catalytic activity of the enzyme itself, a non-enzymatic flavin induced photoisomerization is responsible for the observed zeatin cis trans interconversion in vitro. An overexpression of the maize Nucleotide Pyrophosphatase/phosphodiesterase gene led to decreased FAD and increased FMN and riboflavin contents in transgenic Arabidopsis plants. However, neither contents nor the ratio of zeatin isomers was altered suggesting that the enzyme is unlikely to catalyze the interconversion of zeatin isomers in vivo. Using enhanced expression of a homologous gene, functional Nucleotide Pyrophosphatase/phosphodiesterase was also identified in rice.
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purification of maize Nucleotide Pyrophosphatase phosphodiesterase casts doubt on the existence of zeatin cis trans isomerase in plants
Frontiers in Plant Science, 2017Co-Authors: Tomas Hluska, Marek Sebela, Rene Lenobel, Ivo Frebort, Petr GaluszkaAbstract:Almost 25 years ago, an enzyme named zeatin cis trans isomerase from common bean has been described by Bassil et al. in Plant Physiol. (1993) 102: 867-872. The partially purified enzyme required an external addition of FAD and dithiothreitol for the conversion of cis-zeatin to its trans- isomer that occurred only under light. Although an existence of this important enzyme involved in the metabolism of plant hormones cytokinins was generally accepted by plant biologists, the corresponding protein and encoding gene have not been identified to date. Based on the original paper, we purified and identified an enzyme from maize, which shows the described zeatin cis trans isomerase activity. The enzyme belongs to Nucleotide Pyrophosphatase/phosphodiesterase family, which is well characterized in mammals, but less known in plants. Further experiments with the recombinant maize enzyme obtained from yeast expression system showed that rather than the catalytic activity of the enzyme itself, a non-enzymatic flavin induced photoisomerization is responsible for the observed zeatin cis trans interconversion in vitro. An overexpression of the maize Nucleotide Pyrophosphatase/phosphodiesterase gene led to decreased FAD and increased FMN and riboflavin contents in transgenic Arabidopsis plants. However, neither contents nor the ratio of zeatin isomers was altered suggesting that the enzyme is unlikely to catalyze the interconversion of zeatin isomers in vivo. Using enhanced expression of a homologous gene, functional Nucleotide Pyrophosphatase/phosphodiesterase was also identified in rice.
Tomas Hluska - One of the best experts on this subject based on the ideXlab platform.
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Purification of Maize Nucleotide Pyrophosphatase/Phosphodiesterase Casts Doubt on the Existence of Zeatin Cis-Trans Isomerase in Plants.
Frontiers in Plant Science, 2017Co-Authors: Tomas Hluska, Marek Sebela, Rene Lenobel, Ivo Frebort, Petr GaluszkaAbstract:Almost 25 years ago, an enzyme named zeatin cis trans isomerase from common bean has been described by Bassil et al. in Plant Physiol. (1993) 102: 867-872. The partially purified enzyme required an external addition of FAD and dithiothreitol for the conversion of cis-zeatin to its trans- isomer that occurred only under light. Although an existence of this important enzyme involved in the metabolism of plant hormones cytokinins was generally accepted by plant biologists, the corresponding protein and encoding gene have not been identified to date. Based on the original paper, we purified and identified an enzyme from maize, which shows the described zeatin cis trans isomerase activity. The enzyme belongs to Nucleotide Pyrophosphatase/phosphodiesterase family, which is well characterized in mammals, but less known in plants. Further experiments with the recombinant maize enzyme obtained from yeast expression system showed that rather than the catalytic activity of the enzyme itself, a non-enzymatic flavin induced photoisomerization is responsible for the observed zeatin cis trans interconversion in vitro. An overexpression of the maize Nucleotide Pyrophosphatase/phosphodiesterase gene led to decreased FAD and increased FMN and riboflavin contents in transgenic Arabidopsis plants. However, neither contents nor the ratio of zeatin isomers was altered suggesting that the enzyme is unlikely to catalyze the interconversion of zeatin isomers in vivo. Using enhanced expression of a homologous gene, functional Nucleotide Pyrophosphatase/phosphodiesterase was also identified in rice.
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purification of maize Nucleotide Pyrophosphatase phosphodiesterase casts doubt on the existence of zeatin cis trans isomerase in plants
Frontiers in Plant Science, 2017Co-Authors: Tomas Hluska, Marek Sebela, Rene Lenobel, Ivo Frebort, Petr GaluszkaAbstract:Almost 25 years ago, an enzyme named zeatin cis trans isomerase from common bean has been described by Bassil et al. in Plant Physiol. (1993) 102: 867-872. The partially purified enzyme required an external addition of FAD and dithiothreitol for the conversion of cis-zeatin to its trans- isomer that occurred only under light. Although an existence of this important enzyme involved in the metabolism of plant hormones cytokinins was generally accepted by plant biologists, the corresponding protein and encoding gene have not been identified to date. Based on the original paper, we purified and identified an enzyme from maize, which shows the described zeatin cis trans isomerase activity. The enzyme belongs to Nucleotide Pyrophosphatase/phosphodiesterase family, which is well characterized in mammals, but less known in plants. Further experiments with the recombinant maize enzyme obtained from yeast expression system showed that rather than the catalytic activity of the enzyme itself, a non-enzymatic flavin induced photoisomerization is responsible for the observed zeatin cis trans interconversion in vitro. An overexpression of the maize Nucleotide Pyrophosphatase/phosphodiesterase gene led to decreased FAD and increased FMN and riboflavin contents in transgenic Arabidopsis plants. However, neither contents nor the ratio of zeatin isomers was altered suggesting that the enzyme is unlikely to catalyze the interconversion of zeatin isomers in vivo. Using enhanced expression of a homologous gene, functional Nucleotide Pyrophosphatase/phosphodiesterase was also identified in rice.
S J Craftsbrandner - One of the best experts on this subject based on the ideXlab platform.
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purification and properties of a unique Nucleotide Pyrophosphatase phosphodiesterase i that accumulates in soybean leaves in response to fruit removal
Plant Physiology, 1995Co-Authors: Michael E Salvucci, S J CraftsbrandnerAbstract:Several unique proteins accumulate in soybean (Glycine max) leaves when the developing fruits are removed. In the present study, elevated levels of Nucleotide Pyrophosphatase and phosphodiesterase I activities were present in leaves of defruited soybean plants. The soluble enzyme catalyzing these reactions was purified nearly 1000-fold, producing a preparation that contained a single 72-kD polypeptide. The molecular mass of the holoenzyme was approximately 560 kD, indicating that the native enzyme was likely octameric. The purified enzyme hydrolyzed Nucleotide-sugars, Nucleotide di- and triphosphates, thymidine monophosphate p-nitrophenol, and inorganic pyrophosphate but not Nucleotide monophosphates, sugar mono- and bisphosphates, or NADH. The subunit and holoenzyme molecular masses and the preference for substrates distinguish the soybean leaf Nucleotide Pyrophosphatase/phosphodiesterase I from other plant Nucleotide Pyrophosphatase/phosphodiesterase I enzymes. Also, the N-terminal sequence of the soybean leaf enzyme exhibited no similarity to the mammalian Nucleotide Pyrophosphatase/phosphodiesterase I, soybean vegetative storage proteins, or other entries in the data bank. Thus, the soybean leaf Nucleotide Pyrophosphatase/phosphodiesterase I appears to be a heretofore undescribed protein that is physically and enzymatically distinct from Nucleotide Pyrophosphatase/phosphodiesterase I from other sources, as well as from other phosphohydrolytic enzymes that accumulate in soybean leaves in response to fruit removal.
Ivo Frebort - One of the best experts on this subject based on the ideXlab platform.
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Purification of Maize Nucleotide Pyrophosphatase/Phosphodiesterase Casts Doubt on the Existence of Zeatin Cis-Trans Isomerase in Plants.
Frontiers in Plant Science, 2017Co-Authors: Tomas Hluska, Marek Sebela, Rene Lenobel, Ivo Frebort, Petr GaluszkaAbstract:Almost 25 years ago, an enzyme named zeatin cis trans isomerase from common bean has been described by Bassil et al. in Plant Physiol. (1993) 102: 867-872. The partially purified enzyme required an external addition of FAD and dithiothreitol for the conversion of cis-zeatin to its trans- isomer that occurred only under light. Although an existence of this important enzyme involved in the metabolism of plant hormones cytokinins was generally accepted by plant biologists, the corresponding protein and encoding gene have not been identified to date. Based on the original paper, we purified and identified an enzyme from maize, which shows the described zeatin cis trans isomerase activity. The enzyme belongs to Nucleotide Pyrophosphatase/phosphodiesterase family, which is well characterized in mammals, but less known in plants. Further experiments with the recombinant maize enzyme obtained from yeast expression system showed that rather than the catalytic activity of the enzyme itself, a non-enzymatic flavin induced photoisomerization is responsible for the observed zeatin cis trans interconversion in vitro. An overexpression of the maize Nucleotide Pyrophosphatase/phosphodiesterase gene led to decreased FAD and increased FMN and riboflavin contents in transgenic Arabidopsis plants. However, neither contents nor the ratio of zeatin isomers was altered suggesting that the enzyme is unlikely to catalyze the interconversion of zeatin isomers in vivo. Using enhanced expression of a homologous gene, functional Nucleotide Pyrophosphatase/phosphodiesterase was also identified in rice.
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purification of maize Nucleotide Pyrophosphatase phosphodiesterase casts doubt on the existence of zeatin cis trans isomerase in plants
Frontiers in Plant Science, 2017Co-Authors: Tomas Hluska, Marek Sebela, Rene Lenobel, Ivo Frebort, Petr GaluszkaAbstract:Almost 25 years ago, an enzyme named zeatin cis trans isomerase from common bean has been described by Bassil et al. in Plant Physiol. (1993) 102: 867-872. The partially purified enzyme required an external addition of FAD and dithiothreitol for the conversion of cis-zeatin to its trans- isomer that occurred only under light. Although an existence of this important enzyme involved in the metabolism of plant hormones cytokinins was generally accepted by plant biologists, the corresponding protein and encoding gene have not been identified to date. Based on the original paper, we purified and identified an enzyme from maize, which shows the described zeatin cis trans isomerase activity. The enzyme belongs to Nucleotide Pyrophosphatase/phosphodiesterase family, which is well characterized in mammals, but less known in plants. Further experiments with the recombinant maize enzyme obtained from yeast expression system showed that rather than the catalytic activity of the enzyme itself, a non-enzymatic flavin induced photoisomerization is responsible for the observed zeatin cis trans interconversion in vitro. An overexpression of the maize Nucleotide Pyrophosphatase/phosphodiesterase gene led to decreased FAD and increased FMN and riboflavin contents in transgenic Arabidopsis plants. However, neither contents nor the ratio of zeatin isomers was altered suggesting that the enzyme is unlikely to catalyze the interconversion of zeatin isomers in vivo. Using enhanced expression of a homologous gene, functional Nucleotide Pyrophosphatase/phosphodiesterase was also identified in rice.
Rene Lenobel - One of the best experts on this subject based on the ideXlab platform.
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Purification of Maize Nucleotide Pyrophosphatase/Phosphodiesterase Casts Doubt on the Existence of Zeatin Cis-Trans Isomerase in Plants.
Frontiers in Plant Science, 2017Co-Authors: Tomas Hluska, Marek Sebela, Rene Lenobel, Ivo Frebort, Petr GaluszkaAbstract:Almost 25 years ago, an enzyme named zeatin cis trans isomerase from common bean has been described by Bassil et al. in Plant Physiol. (1993) 102: 867-872. The partially purified enzyme required an external addition of FAD and dithiothreitol for the conversion of cis-zeatin to its trans- isomer that occurred only under light. Although an existence of this important enzyme involved in the metabolism of plant hormones cytokinins was generally accepted by plant biologists, the corresponding protein and encoding gene have not been identified to date. Based on the original paper, we purified and identified an enzyme from maize, which shows the described zeatin cis trans isomerase activity. The enzyme belongs to Nucleotide Pyrophosphatase/phosphodiesterase family, which is well characterized in mammals, but less known in plants. Further experiments with the recombinant maize enzyme obtained from yeast expression system showed that rather than the catalytic activity of the enzyme itself, a non-enzymatic flavin induced photoisomerization is responsible for the observed zeatin cis trans interconversion in vitro. An overexpression of the maize Nucleotide Pyrophosphatase/phosphodiesterase gene led to decreased FAD and increased FMN and riboflavin contents in transgenic Arabidopsis plants. However, neither contents nor the ratio of zeatin isomers was altered suggesting that the enzyme is unlikely to catalyze the interconversion of zeatin isomers in vivo. Using enhanced expression of a homologous gene, functional Nucleotide Pyrophosphatase/phosphodiesterase was also identified in rice.
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purification of maize Nucleotide Pyrophosphatase phosphodiesterase casts doubt on the existence of zeatin cis trans isomerase in plants
Frontiers in Plant Science, 2017Co-Authors: Tomas Hluska, Marek Sebela, Rene Lenobel, Ivo Frebort, Petr GaluszkaAbstract:Almost 25 years ago, an enzyme named zeatin cis trans isomerase from common bean has been described by Bassil et al. in Plant Physiol. (1993) 102: 867-872. The partially purified enzyme required an external addition of FAD and dithiothreitol for the conversion of cis-zeatin to its trans- isomer that occurred only under light. Although an existence of this important enzyme involved in the metabolism of plant hormones cytokinins was generally accepted by plant biologists, the corresponding protein and encoding gene have not been identified to date. Based on the original paper, we purified and identified an enzyme from maize, which shows the described zeatin cis trans isomerase activity. The enzyme belongs to Nucleotide Pyrophosphatase/phosphodiesterase family, which is well characterized in mammals, but less known in plants. Further experiments with the recombinant maize enzyme obtained from yeast expression system showed that rather than the catalytic activity of the enzyme itself, a non-enzymatic flavin induced photoisomerization is responsible for the observed zeatin cis trans interconversion in vitro. An overexpression of the maize Nucleotide Pyrophosphatase/phosphodiesterase gene led to decreased FAD and increased FMN and riboflavin contents in transgenic Arabidopsis plants. However, neither contents nor the ratio of zeatin isomers was altered suggesting that the enzyme is unlikely to catalyze the interconversion of zeatin isomers in vivo. Using enhanced expression of a homologous gene, functional Nucleotide Pyrophosphatase/phosphodiesterase was also identified in rice.
