The kinetic properties of glutamine synthetase (EC 6.3.1.2) isolated from pea chloroplasts and purified according to the previously developed procedure have been investigated. The pH optimum for the enzymatic reaction in the presence of Mg2+ and Mn2+ are 7.5-7.6 and 5.5, respectively. The corresponding values of the activation energy per enzyme monomer (Mr = 60 000) are equal to 2900 and 1190 cal/mole. With Mg2+ the values of Km(app.) for NH4+, NH2OH, L-glutamate (+NH4+), L-glutamate (+NH2OH), ATP(+NH4+ and NH2OH) and Mg-ATP (+NH4+ and NH2OH) are 0.64, 17.5, 5.6, 7.0, 1.3 and 0.74 mM, respectively.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Glioprotective Effects of Resveratrol Against Glutamate-Induced Cellular Dysfunction: The Role of Heme Oxygenase 1 Pathway.
Neurotox Res
January 2025
Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Resveratrol, a natural polyphenol, has shown promising neuroprotective effects in several in vivo and in vitro experimental models. However, the mechanisms by which resveratrol mediates these effects are not fully understood. Glutamate is the major excitatory neurotransmitter in the brain; however, excessive extracellular glutamate levels can affect neural activity in several neurological diseases.
View Article and Find Full Text PDFIntegrated physiological, transcriptomic and metabolomic analyses reveal potential mechanisms of potato tuber dormancy release.
Physiol Plant
January 2025
School of Agriculture, Yunnan University, Kunming, Yunnan, China.
Regulating potato tuber dormancy is crucial for crop productivity and food security. We conducted the first comprehensive physiological, transcriptomic, and metabolomic investigations of two varieties of long and short dormant potato tubers in order to clarify the mechanisms of dormancy release. In the current study, three different dormant stages of UGT (ungerminated tubers), MGT (minimally germinated tubers), and GT (germinated tubers) were obtained by treatment with the germination promoter gibberellin A and the germination inhibitor chlorpropham.
View Article and Find Full Text PDFAmmonia-Assimilating Bacteria Promote Wheat () Growth and Nitrogen Utilization.
Microorganisms
December 2024
Key Laboratory of Enzyme Engineering of Agricultural Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Henan Agricultural University, Zhengzhou 450046, China.
Nitrogen fertilizers in agriculture often suffer losses. Ammonia-assimilating bacteria can immobilize ammonia and reduce these losses, but they have not been used in agriculture. This study identified an ammonia-assimilating strain, sp.
View Article and Find Full Text PDFDeciphering the impact of NOS-derived NO on nitrogen metabolism and carbon flux in the heterocytous cyanobacterium Aphanizomenon flos-aquae 2012/KM1/D3.
Plant Physiol Biochem
January 2025
Laboratory of Microbial Genetics, Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India. Electronic address:
Nitric oxide synthases (NOSs) are heme-based monooxygenases that catalyze the NADPH-dependent oxidation of L-arginine to produce NO and L-citrulline. Over the past five years, the identification and characterization of NOS homologs in cyanobacteria have significantly advanced our understanding of these enzymes. However, the precise mechanisms through which NOS-derived NO influences nitrogen metabolism remain incompletely elucidated.
View Article and Find Full Text PDFRegulation of anaplerotic enzymes by melatonin enhances resilience to cadmium toxicity in Vigna radiata (L.) R. Wilczek.
Plant Physiol Biochem
January 2025
Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia.
Melatonin (Mel) is a tryptophan-derived (N-acetyl-5-methoxytryptamine) molecule. In the present study, role of Mel in the regulation of various anaplerotic enzymes is discussed in relation to N metabolism and H-ATPase activity in mung bean under Cd stress. The application of Mel to the Cd-stressed mung bean seedlings was remarkable in improving the activity of hexokinase (35.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!