Journal articles: 'Glycine Metabolism'

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Schmidt, S., and G. R. Stewart. "Glycine metabolism by plant roots and its occurrence in Australian plant communities." Functional Plant Biology 26, no. 3 (1999): 253. http://dx.doi.org/10.1071/pp98116.

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Soluble organic nitrogen, including protein and amino acids, was found to be a ubiquitous form of soil N in diverse Australian environments. Fine roots of species representative of these environments were found to be active in the metabolism of glycine. The ability to incorporate [15N]glycine was widespread among plant species from subantarctic to tropical communities. In species from subantarctic herbfield, subtropical coral cay, subtropical rainforest and wet heathland, [15N]glycine incorporation ranged from 26 to 45 % of 15NH4+ incorporation and was 2- to 3-fold greater than 15NO3- incorporation. Most semiarid mulga and tropical savanna woodland species incorporated [15N]glycine and 15NO3- in similar amounts, 18–26 % of 15NH4+ incorporation. We conclude that the potential to utilise amino acids as N sources is of widespread occurrence in plant communities and is not restricted to those from low temperature regimes or where N mineralisation is limited. Seedlings of Hakea (Proteaceae) were shown to metabolise glycine, with a rapid transfer of 15N from glycine to serine and other amino compounds. The ability to take up and metabolise glycine was unaffected by the presence of equimolar concentrations of NO3- and NH4+. Isonicotinic acid hydrazide (INH) did not inhibit the transfer of 15N- label from glycine to serine indicating that serine hydroxymethyltransferase was not active in glycine catabolism. In contrast aminooxyacetate (AOA) strongly inhibited transfer of 15N from glycine to serine and labelling of other amino compounds, suggesting that glycine is metabolised in roots and cluster roots of Hakea via an aminotransferase.

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Andreesen, Jan R. "Glycine metabolism in anaerobes." Antonie van Leeuwenhoek 66, no. 1-3 (1994): 223–37. http://dx.doi.org/10.1007/bf00871641.

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Oliver, David J., Michel Neuburger, Jacques Bourguignon, and Roland Douce. "Glycine metabolism by plant mitochondria." Physiologia Plantarum 80, no. 3 (November 1990): 487–91. http://dx.doi.org/10.1111/j.1399-3054.1990.tb00072.x.

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Koopman, René, Marissa K. Caldow, Daniel J. Ham, and Gordon S. Lynch. "Glycine metabolism in skeletal muscle." Current Opinion in Clinical Nutrition & Metabolic Care 20, no. 4 (July 2017): 237–42. http://dx.doi.org/10.1097/mco.0000000000000383.

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Oliver, David J., Michel Neuburger, Jacques Bourguignon, and Roland Douce. "Glycine metabolism by plant mitochondria." Physiologia Plantarum 80, no. 3 (November 1990): 487–91. http://dx.doi.org/10.1034/j.1399-3054.1990.800324.x.

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6

Sánchez-Castillo, Anaís, Marc Vooijs, and Kim R. Kampen. "Linking Serine/Glycine Metabolism to Radiotherapy Resistance." Cancers 13, no. 6 (March 10, 2021): 1191. http://dx.doi.org/10.3390/cancers13061191.

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The activation of de novo serine/glycine biosynthesis in a subset of tumors has been described as a major contributor to tumor pathogenesis, poor outcome, and treatment resistance. Amplifications and mutations of de novo serine/glycine biosynthesis enzymes can trigger pathway activation; however, a large group of cancers displays serine/glycine pathway overexpression induced by oncogenic drivers and unknown regulatory mechanisms. A better understanding of the regulatory network of de novo serine/glycine biosynthesis activation in cancer might be essential to unveil opportunities to target tumor heterogeneity and therapy resistance. In the current review, we describe how the activation of de novo serine/glycine biosynthesis in cancer is linked to treatment resistance and its implications in the clinic. To our knowledge, only a few studies have identified this pathway as metabolic reprogramming of cancer cells in response to radiation therapy. We propose an important contribution of de novo serine/glycine biosynthesis pathway activation to radioresistance by being involved in cancer cell viability and proliferation, maintenance of cancer stem cells (CSCs), and redox homeostasis under hypoxia and nutrient-deprived conditions. Current approaches for inhibition of the de novo serine/glycine biosynthesis pathway provide new opportunities for therapeutic intervention, which in combination with radiotherapy might be a promising strategy for tumor control and ultimately eradication. Further research is needed to gain molecular and mechanistic insight into the activation of this pathway in response to radiation therapy and to design sophisticated stratification methods to select patients that might benefit from serine/glycine metabolism-targeted therapies in combination with radiotherapy.

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House, James D., Beatrice N. Hall, and John T. Brosnan. "Threonine metabolism in isolated rat hepatocytes." American Journal of Physiology-Endocrinology and Metabolism 281, no. 6 (December 1, 2001): E1300—E1307. http://dx.doi.org/10.1152/ajpendo.2001.281.6.e1300.

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The removal of the 1-carbon of threonine can occur via threonine dehydrogenase or threonine aldolase, this carbon ending up in glycine to be liberated by the mitochondrial glycine cleavage system and producing CO2. Alternatively, in the threonine dehydratase pathway, the 1-carbon ends up in α-ketobutyrate, which is oxidized in the mitochondria to CO2. Rat hepatocytes, incubated in Krebs-Henseleit medium, were incubated with 0.5 mMl-[1-14C]threonine, and14CO2 production was measured. Added glycine (0.3 mM) marginally suppressed threonine oxidation. Cysteamine (0.5 mM), a potent inhibitor of the glycine cleavage system, reduced threonine oxidation to 65% of controls. However, α-cyanocinnamate (0.5 mM), a competitive inhibitor of mitochondrial α-keto acid uptake, reduced threonine oxidation to 35% of controls. These data provided strong evidence that ∼65% of threonine oxidation occurs through the glycine-independent threonine dehydratase pathway. Glucagon (10−7 M) increased threonine oxidation and stimulated threonine uptake by these cells. In summary, the majority of threonine oxidation occurs through the threonine dehydratase pathway in rat hepatocytes, and threonine oxidation is increased by glucagon, which also increases threonine's transport.

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Alves, Anaïs, Arthur Bassot, Anne-Laure Bulteau, Luciano Pirola, and Béatrice Morio. "Glycine Metabolism and Its Alterations in Obesity and Metabolic Diseases." Nutrients 11, no. 6 (June 16, 2019): 1356. http://dx.doi.org/10.3390/nu11061356.

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Glycine is the proteinogenic amino-acid of lowest molecular weight, harboring a hydrogen atom as a side-chain. In addition to being a building-block for proteins, glycine is also required for multiple metabolic pathways, such as glutathione synthesis and regulation of one-carbon metabolism. Although generally viewed as a non-essential amino-acid, because it can be endogenously synthesized to a certain extent, glycine has also been suggested as a conditionally essential amino acid. In metabolic disorders associated with obesity, type 2 diabetes (T2DM), and non-alcoholic fatty liver disease (NAFLDs), lower circulating glycine levels have been consistently observed, and clinical studies suggest the existence of beneficial effects induced by glycine supplementation. The present review aims at synthesizing the recent advances in glycine metabolism, pinpointing its main metabolic pathways, identifying the causes leading to glycine deficiency—especially in obesity and associated metabolic disorders—and evaluating the potential benefits of increasing glycine availability to curb the progression of obesity and obesity-related metabolic disturbances. This study focuses on the importance of diet, gut microbiota, and liver metabolism in determining glycine availability in obesity and associated metabolic disorders.

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Amelio, Ivano, Francesca Cutruzzolá, Alexey Antonov, Massimiliano Agostini, and Gerry Melino. "Serine and glycine metabolism in cancer." Trends in Biochemical Sciences 39, no. 4 (April 2014): 191–98. http://dx.doi.org/10.1016/j.tibs.2014.02.004.

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Li, Yuchen, Kai Fan, Jiazhi Shen, Yu Wang, Anburaj Jeyaraj, Shunkai Hu, Xuan Chen, Zhaotang Ding, and Xinghui Li. "Glycine-Induced Phosphorylation Plays a Pivotal Role in Energy Metabolism in Roots and Amino Acid Metabolism in Leaves of Tea Plant." Foods 12, no. 2 (January 10, 2023): 334. http://dx.doi.org/10.3390/foods12020334.

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Phosphorylation is the most extensive post-translational modification of proteins and thus regulates plant growth. However, the regulatory mechanism of phosphorylation modification on the growth of tea plants caused by organic nitrogen is still unclear. In order to explore the phosphorylation modification mechanism of tea plants in response to organic nitrogen, we used glycine as the only nitrogen source and determined and analyzed the phosphorylated proteins in tea plants by phosphoproteomic analysis. The results showed that the phosphorylation modification induced by glycine-supply played important roles in the regulation of energy metabolism in tea roots and amino acid metabolism in tea leaves. In roots, glycine-supply induced dephosphorylation of proteins, such as fructose-bisphosphate aldolase cytoplasmic isozyme, glyceraldehyde-3-phosphate dehydrogenase, and phosphoenolpyruvate carboxylase, resulted in increased intensity of glycolysis and decreased intensity of tricarboxylic acid cycle. In leaves, the glycine-supply changed the phosphorylation levels of glycine dehydrogenase, aminomethyltransferase, glutamine synthetase, and ferredoxin-dependent glutamate synthase, which accelerated the decomposition of glycine and enhanced the ability of ammonia assimilation. In addition, glycine-supply could improve the tea quality by increasing the intensity of amino acids, such as theanine and alanine. This research clarified the important regulatory mechanism of amino acid nitrogen on tea plant growth and development through protein phosphorylation.

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Rybicka, Hanna. "Metabolism of hypoxanthine in wheat shoots." Acta Societatis Botanicorum Poloniae 43, no. 4 (2015): 485–89. http://dx.doi.org/10.5586/asbp.1974.046.

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The incorporation of [<sup>14</sup>C] glycine and [8-<sup>l4</sup>C] hypoxanthine to some purine derivatives in overground parts of wheat seedlings was studied. It was found that adenylic acid could be synthesized from glycine and also from free hypoxanthine and in both processes inosinic acid is an intermediate metabolite.

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Lowry, M., D. E. Hall, M. S. Hall, and J. T. Brosnan. "Renal metabolism of amino acids in vivo: studies on serine and glycine fluxes." American Journal of Physiology-Renal Physiology 252, no. 2 (February 1, 1987): F304—F309. http://dx.doi.org/10.1152/ajprenal.1987.252.2.f304.

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The pathway of serine synthesis by the rat kidney has been investigated in vivo by measuring the net flux in the presence and absence of specific inhibitors of the glycine cleavage system, phosphoenol-pyruvate carboxykinase and gamma-glutamyltranspeptidase. In normal animals serine release was 705 +/- 187 nmol X min-1 X animal-1, whereas glycine uptake was only 28% of this value. Inhibition of the glycine cleavage system (cysteamine infusion) resulted in a reversal of glycine flux with no change in serine production. In similar experiments with mercaptopicolinate serine release was decreased by 55% with no change in glycine removal. AT-125, a potent inhibitor of gamma-glutamyltranspeptidase, had no effect on renal serine and glycine fluxes. In chronically acidotic rats serine synthesis was unchanged, but there were significant increases in the uptake of glutamine (fourfold) and glycine (2.5-fold). Infusion of cysteamine into these animals caused a 50% decrease in serine release with a significant reversal of the glycine flux. Infusion of mercaptopicolinate had effects similar to those observed in normal animals. These results show that renal serine synthesis can occur by both the phosphorylated-intermediate pathway and serine hydroxymethyltransferase in vivo. Furthermore, they demonstrate that glycine can contribute significantly to ammoniagenesis during acidosis.

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13

Weinberg, J. M., D. N. Buchanan, J. A. Davis, and M. Abarzua. "Metabolic aspects of protection by glycine against hypoxic injury to isolated proximal tubules." Journal of the American Society of Nephrology 1, no. 7 (January 1991): 949–58. http://dx.doi.org/10.1681/asn.v17949.

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To clarify the roles of butyrate and acylglycine formation in hypoxic proximal tubule cell injury and protection by glycine and to test the contribution of iodoacetate-suppressible metabolism to protection, (1) it was determined whether protection by glycine is fully expressed when glucose, lactate, alanine, and butyrate are replaced by alpha-ketoglutarate as the sole substrate for the tubules, (2) butyrate metabolism and acylglycine formation were directly measured in control and hypoxic preparations, and (3) it was assessed whether injury produced by iodoacetate, a potent inhibitor of glycolytic metabolism, is subject to protection by glycine. Susceptibility to hypoxic injury in medium with alpha-ketoglutarate as the sole substrate was similar to that seen in medium containing glucose, lactate, alanine, and butyrate. Tubules in alpha-ketoglutarate medium showed high degrees of protection by glycine against injury produced by 30-min of hypoxia, by iodoacetate alone, and by iodoacetate combined with hypoxia. Protection did not require preservation of cell ATP or glutathione. In glucose-lactate-alanine-butyrate medium, butyrate, measured by gas chromatography, was rapidly metabolized by oxygenated tubules and fully accounted for basal rates of oxygen consumption. Butyrate utilization stopped during hypoxia. Neither aspect of butyrate metabolism was altered by glycine. Formation of acylglycines was assessed by gas chromatography/mass spectroscopy. In preparations treated with glycine, butyrylglycine was detected under both oxygenated and hypoxic conditions; the quantities, however, were small and no other acylglycines were found. These observations indicate that protective effects of glycine are independent of short-chain acylglycine formation and glycolytic metabolism.

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14

Razak, Meerza Abdul, Pathan Shajahan Begum, Buddolla Viswanath, and Senthilkumar Rajagopal. "Multifarious Beneficial Effect of Nonessential Amino Acid, Glycine: A Review." Oxidative Medicine and Cellular Longevity 2017 (2017): 1–8. http://dx.doi.org/10.1155/2017/1716701.

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Glycine is most important and simple, nonessential amino acid in humans, animals, and many mammals. Generally, glycine is synthesized from choline, serine, hydroxyproline, and threonine through interorgan metabolism in which kidneys and liver are the primarily involved. Generally in common feeding conditions, glycine is not sufficiently synthesized in humans, animals, and birds. Glycine acts as precursor for several key metabolites of low molecular weight such as creatine, glutathione, haem, purines, and porphyrins. Glycine is very effective in improving the health and supports the growth and well-being of humans and animals. There are overwhelming reports supporting the role of supplementary glycine in prevention of many diseases and disorders including cancer. Dietary supplementation of proper dose of glycine is effectual in treating metabolic disorders in patients with cardiovascular diseases, several inflammatory diseases, obesity, cancers, and diabetes. Glycine also has the property to enhance the quality of sleep and neurological functions. In this review we will focus on the metabolism of glycine in humans and animals and the recent findings and advances about the beneficial effects and protection of glycine in different disease states.

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WHATLEY, F. R., W. C. GREENAWAY, and R. H. DUNSTAN. "Metabolism of glycine in carrot culture cells." Biochemical Society Transactions 14, no. 1 (February 1, 1986): 112–13. http://dx.doi.org/10.1042/bst0140112.

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Cortinovis, S., V. Lucini, and A. Lucca. "SERINE AND GLYCINE METABOLISM IN SCHIZOPHRENIC PATIENTS." Clinical Neuropharmacology 15 (1992): 604B. http://dx.doi.org/10.1097/00002826-199202001-01178.

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17

Baruah, Sankar, Rafiq Waziri, and Arnold Sherman. "Neuroleptic effects on serine and glycine metabolism." Biological Psychiatry 34, no. 8 (October 1993): 544–50. http://dx.doi.org/10.1016/0006-3223(93)90197-l.

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Lucca, Adelio, Sebastiano Cortinovis, and Valentina Lucini. "Serine and glycine metabolism in schizophrenic patients." Progress in Neuro-Psychopharmacology and Biological Psychiatry 17, no. 6 (November 1993): 947–53. http://dx.doi.org/10.1016/0278-5846(93)90022-k.

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19

Adeva-Andany, M., G. Souto-Adeva, E. Ameneiros-Rodríguez, C. Fernández-Fernández, C. Donapetry-García, and A. Domínguez-Montero. "Insulin resistance and glycine metabolism in humans." Amino Acids 50, no. 1 (November 1, 2017): 11–27. http://dx.doi.org/10.1007/s00726-017-2508-0.

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20

Beynen, A. C., and A. G. Lemmens. "Dietary glycine and cholesterol metabolism in rats." Zeitschrift für Ernährungswissenschaft 26, no. 3 (September 1987): 161–64. http://dx.doi.org/10.1007/bf02039137.

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21

NARKEWICZ, Michael R., S. David SAULS, Susan S. TJOA, Cecilia TENG, and Paul V. FENNESSEY. "Evidence for intracellular partitioning of serine and glycine metabolism in Chinese hamster ovary cells." Biochemical Journal 313, no. 3 (February 1, 1996): 991–96. http://dx.doi.org/10.1042/bj3130991.

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Serine hydroxymethyltransferase (SHMT) is the primary enzyme in the interconversion of serine and glycine. The roles of mitochondrial and cytosolic SHMT in the interconversion of serine and glycine were determined in two Chinese hamster ovary (CHO) cell lines that both contain cytosolic SHMT but either have (CHOm+) or lack (CHOm-) mitochondrial SHMT. Mitochondrial SHMT activity was significantly reduced in CHOm- (0.24±0.11 nmol/min per mg of mitochondrial protein) compared with CHOm+ (3.21±0.66 nmol/min per mg of mitochondrial protein; P = 0.02) cells, whereas cytosolic SHMT activity was similar in CHOm- and CHOm+ cells (1.09±0.31 and 1.53±0.12 nmol/min per mg of cytosolic protein respectively; P = 0.57). In CHOm+ and CHOm- cells, the relative flux of glycine to serine measured with either [1-13C]- or [2-13C]-glycine was similar (CHOm-: 538±82 nmol/24 per mg of DNA; CHOm+: 616±88 nmol/24 h per mg of DNA; P = 0.42). In contrast, the relative flux of serine to glycine measured with [1-13C]serine was low in CHOm- cells (80±28 nmol/24 h per mg of DNA) compared with CHOm+ cells (3080±320 nmol/24 h per mg of DNA; P = 0.0001). The rate of glycine production determined by UA-2[1-13C]glycine dilution was lower in CHOm- (1200±200 nmol/24 h per mg of DNA) than CHOm+ (10200±1800 nmol/24 h per mg of DNA; P = 0.03) cells, whereas glycine utilization was similar in the two cell lines. Serine production was similar in the two cell lines but serine utilization was lower in CHOm- (3800±1200 μmol/24 h per mg of DNA) than CHOm+ (6600±1000 nmol/24 h per mg of DNA; P = 0.0002) cells. Increasing the serine concentration in the medium resulted in an increase in glycine production in CHOm+ but not in CHOm- cells. Intracellular studies with [1-13C]serine confirm the findings of decreased glycine production from serine. In CHO cells there is partitioning of intracellular serine and glycine metabolism. Our data support the hypothesis that mitochondrial SHMT is the primary pathway for serine into glycine interconversion.

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Patel, D. K., A. Ogunbona, L. J. Notarianni, and P. N. Bennett. "Depletion of Plasma Glycine and Effect of Glycine by Mouth on Salicylate Metabolism During Aspirin Overdose." Human & Experimental Toxicology 9, no. 6 (November 1990): 389–95. http://dx.doi.org/10.1177/096032719000900606.

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1 The metabolism of aspirin was investigated in 45 patients who had taken self-administered overdose of aspirin and were treated with fluids only, glycine, N-glycylglycine by mouth, or by sodium bicarbonate i.v. 2 The major metabolite recovered in the urine of patients treated with oral fluids, glycine or N-glycylglycine was salicyluric acid, which accounted for means of 51%, 47% and 38% of the total, respectively; salicylic acid comprised 19%, 29% and 29%. In contrast, salicylic acid (42%) was the major urinary metabolite recovered from patients treated with sodium bicarbonate. 3 Plasma glycine concentrations in healthy volunteers who had taken no aspirin remained constant through the day and were not affected by a therapeutic dose (500 mg) of aspirin. Plasma glycine was consistently lower in patients with aspirin overdose than in these healthy volunteers, suggesting depletion of available glycine. 4 Orally administered glycine and N-glycylglycine increased plasma glycine. While the fraction of total salicylate recovered as salicyluric acid was not altered, the maximum rate of excretion of salicyluric acid was higher in patients who received glycine than in the control group; there was no significant difference in the maximum rate of excretion of salicyluric acid between the group that received glycine and the group that received N-glycylglycine. 5 The data suggest that exogenous glycine increases the rate of formation of salicyluric acid in salicylate overdose.

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Hansen, C. P., F. Stadil, L. Yucun, and J. F. Rehfeld. "Pharmacokinetics and organ metabolism of carboxyamidated and glycine-extended gastrins in pigs." American Journal of Physiology-Gastrointestinal and Liver Physiology 271, no. 1 (July 1, 1996): G156—G163. http://dx.doi.org/10.1152/ajpgi.1996.271.1.g156.

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The elimination of carboxyamidated gastrin-17 and its glycine-extended precursor was studied in anesthetized pigs during constant-rate infusion. Extraction of amidated gastrin-17 was recorded in the hindlimb (42%), kidney (40%), head (32%, P < 0.001), and the gut (13%, P < 0.01). Elimination was not recorded in the liver, lungs, or heart. Extraction of glycine-extended gastrin-17 was measured in the kidney (36%), hindlimb (31%, P < 0.001), head (26%), and the gut (16%, P < 0.01), but not in the liver or the lungs. Glycine-extended gastrin-17 was not processed to amidated gastrin during infusion. The half-life, metabolic clearance rate, and apparent volume of distribution for amidated gastrin-17 were 3.5 +/- 0.4 min, 15.5 +/- 1.1 ml.kg-1.min-1, and 76.5 +/- 9.9 ml/kg, respectively, and for glycine-extended gastrin-17 were 4.3 +/- 0.6 min, 17.4 +/- 0.9 ml.kg-1.min-1, and 104.7 +/- 11.9 ml/kg, respectively. We conclude that extraction of amidated and glycine-extended gastrin-17 varies in the vascular beds, with elimination mainly confined to nonorgan tissues and the kidneys.

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Tan, Yee-Ling, Nga-Lai Sou, Feng-Yao Tang, Hsin-An Ko, Wei-Ting Yeh, Jian-Hau Peng, and En-Pei Isabel Chiang. "Tracing Metabolic Fate of Mitochondrial Glycine Cleavage System Derived Formate In Vitro and In Vivo." International Journal of Molecular Sciences 21, no. 22 (November 20, 2020): 8808. http://dx.doi.org/10.3390/ijms21228808.

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Folate-mediated one-carbon (1C) metabolism is a major target of many therapies in human diseases. Studies have focused on the metabolism of serine 3-carbon as it serves as a major source for 1C units. The serine 3-carbon enters the mitochondria transferred by folate cofactors and eventually converted to formate and serves as a major building block for cytosolic 1C metabolism. Abnormal glycine metabolism has been reported in many human pathological conditions. The mitochondrial glycine cleavage system (GCS) catalyzes glycine degradation to CO2 and ammonium, while tetrahydrofolate (THF) is converted into 5,10-methylene-THF. GCS accounts for a substantial proportion of whole-body glycine flux in humans, yet the particular metabolic route of glycine 2-carbon recycled from GCS during mitochondria glycine decarboxylation in hepatic or bone marrow 1C metabolism is not fully investigated, due to the limited accessibility of human tissues. Labeled glycine at 2-carbon was given to humans and primary cells in previous studies for investigating its incorporations into purines, its interconversion with serine, or the CO2 production in the mitochondria. Less is known on the metabolic fate of the glycine 2-carbon recycled from the GCS; hence, a model system tracing its metabolic fate would help in this regard. We took the direct approach of isotopic labeling to further explore the in vitro and in vivo metabolic fate of the 2-carbon from [2-13C]glycine and [2-13C]serine. As the 2-carbon of glycine and serine is decarboxylated and catabolized via the GCS, the original 13C-labeled 2-carbon is transferred to THF and yield methyleneTHF in the mitochondria. In human hepatoma cell-lines, 2-carbon from glycine was found to be incorporated into deoxythymidine (dTMP, dT + 1), M + 3 species of purines (deoxyadenine, dA and deoxyguanine, dG), and methionine (Met + 1). In healthy mice, incorporation of GCS-derived formate from glycine 2-carbon was found in serine (Ser + 2 via cytosolic serine hydroxy methyl transferase), methionine, dTMP, and methylcytosine (mC + 1) in bone marrow DNA. In these experiments, labeled glycine 2-carbon directly incorporates into Ser + 1, A + 2, and G + 2 (at C2 and C8 of purine) in the cytosol. It is noteworthy that since the serine 3-carbon is unlabeled in these experiments, the isotopic enrichments in dT + 1, Ser + 2, dA + 3, dG + 3, and Met + 1 solely come from the 2-carbon of glycine/serine recycled from GCS, re-enters the cytosolic 1C metabolism as formate, and then being used for cytosolic syntheses of serine, dTMP, purine (M + 3) and methionine. Taken together, we established model systems and successfully traced the metabolic fate of mitochondrial GCS-derived formate from glycine 2-carbon in vitro and in vivo. Nutritional supply significantly alters formate generation from GCS. More GCS-derived formate was used in hepatic serine and methionine syntheses, whereas more GCS-derived formate was used in dTMP synthesis in the bone marrow, indicating that the utilization and partitioning of GCS-derived 1C unit are tissue-specific. These approaches enable better understanding concerning the utilization of 1C moiety generated from mitochondrial GCS that can help to further elucidate the role of GCS in human disease development and progression in future applications. More studies on GCS using these approaches are underway.

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Kory, Nora, Gregory A. Wyant, Gyan Prakash, Jelmi uit de Bos, Francesca Bottanelli, Michael E. Pacold, Sze Ham Chan, et al. "SFXN1 is a mitochondrial serine transporter required for one-carbon metabolism." Science 362, no. 6416 (November 15, 2018): eaat9528. http://dx.doi.org/10.1126/science.aat9528.

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One-carbon metabolism generates the one-carbon units required to synthesize many critical metabolites, including nucleotides. The pathway has cytosolic and mitochondrial branches, and a key step is the entry, through an unknown mechanism, of serine into mitochondria, where it is converted into glycine and formate. In a CRISPR-based genetic screen in human cells for genes of the mitochondrial pathway, we found sideroflexin 1 (SFXN1), a multipass inner mitochondrial membrane protein of unclear function. Like cells missing mitochondrial components of one-carbon metabolism, those null for SFXN1 are defective in glycine and purine synthesis. Cells lacking SFXN1 and one of its four homologs, SFXN3, have more severe defects, including being auxotrophic for glycine. Purified SFXN1 transports serine in vitro. Thus, SFXN1 functions as a mitochondrial serine transporter in one-carbon metabolism.

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Weinberg, J. M., I. Nissim, N. F. Roeser, J. A. Davis, S. Schultz, and I. Nissim. "Relationships between intracellular amino acid levels and protection against injury to isolated proximal tubules." American Journal of Physiology-Renal Physiology 260, no. 3 (March 1, 1991): F410—F419. http://dx.doi.org/10.1152/ajprenal.1991.260.3.f410.

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Metabolism and cellular levels of glycine, alanine, and other relevant amino acids in proximal tubules were studied during models of acute injury and protection by glycine. Freeze-clamped, normal rabbit renal cortex was very rich in glycine (66.8 nmol/mg protein) and glutamate and also had substantial levels of taurine, alanine, glutamine, serine, and aspartate. Isolated proximal tubules were severely depleted of all these amino acids (glycine, 2.1 nmol/mg protein). During 37 degrees C incubation in presence of alanine, tubules recovered only glutamate to a level approximating that in vivo (38.8 nmol/mg protein, 15.2 mM). Glycine added to medium at levels ranging from 0.25 to 2 mM was actively concentrated four- to sixfold by tubule cells. Two millimolar glycine potently protected tubules from lethal cell injury induced by hypoxia, antimycin A, or ouabain. Glycine levels of injured tubules rapidly equilibrated with medium, irrespective of whether glycine was loaded by preincubation or was added concomitantly with the injury maneuver. Metabolism of glycine during protection, assessed by changes in total levels, gas chromatography-mass spectroscopy determination of the fate of [13C]glycine, and redistribution of label from [3H]glycine was minimal. The data suggest that glycine plays an essential, constitutive role in maintenance of tubule cell structural integrity independently of common metabolic pathways. Intracellular amino acid content is sufficiently labile for depletion of structurally essential amino acids to potentially occur in a variety of settings, but, even with severe ATP depletion or Na+ pump inhibition, supplemental glycine is readily available to intracellular sites of action.

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Olufemi, O. Samson, Paul G. Whittaker, Dave Halliday, and Tom Lind. "Albumin metabolism in fasted subjects during late pregnancy." Clinical Science 81, no. 2 (August 1, 1991): 161–68. http://dx.doi.org/10.1042/cs0810161.

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1. Albumin fractional synthetic rate was determined in five non-pregnant subjects and five normal pregnant subjects in late gestation after an overnight fast by simultaneous prime and intravenous infusion of two precursor amino acids, [15N]glycine and l-[1-13C]leucine, with additional priming of the large but, slowly turning over, urea pool with [15N2]urea. 2. The two tracers yielded similar values of albumin fractional synthetic rate: 6.1 and 6.0%/day in nonpregnant subjects and 7.3 and 7.6%/day in pregnant subjects, for glycine and leucine, respectively. While plasma volume was greater and serum albumin concentration was significantly reduced during pregnancy, the calculated intravascular albumin mass was significantly increased in pregnant subjects. 3. The amount of albumin synthesized in the intravascular compartment was significantly greater at 8.8 and 9.5 g/day in pregnant subjects compared with 6.4 and 6.3 g/day in non-pregnant control subjects (glycine and leucine methods, respectively). Calculated whole-body protein turnover using glycine was not different between the two subject groups, but leucine flux was higher in pregnant subjects. Partitioning of nitrogenous products in urine revealed that pregnant subjects excreted less urea, less ammonia and less creatinine than the non-pregnant control subjects. 4. These findings suggest that whereas the serum albumin concentration decreases during pregnancy secondary to the large increase in plasma volume, there is an increase in albumin synthesis such that total intravascular albumin mass is increased in late pregnancy.

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Lechtenfeld, Mats, Julia Heine, Janin Sameith, Florian Kremp, and Volker Müller. "Glycine betaine metabolism in the acetogenic bacteriumAcetobacterium woodii." Environmental Microbiology 20, no. 12 (October 5, 2018): 4512–25. http://dx.doi.org/10.1111/1462-2920.14389.

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Neeman, Michal, Dvora Aviv, Hadassa Degani, and Esra Galun. "Glucose and Glycine Metabolism in Regenerating Tobacco Protoplasts." Plant Physiology 77, no. 2 (February 1, 1985): 374–78. http://dx.doi.org/10.1104/pp.77.2.374.

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Kohno, Michimori, Takechika Fujii, and Chisato Hirayama. "[15N]glycine metabolism in normal and cirrhotic subjects." Biochemical Medicine and Metabolic Biology 43, no. 3 (June 1990): 201–13. http://dx.doi.org/10.1016/0885-4505(90)90026-w.

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Kalhan, Satish C., Lourdes L. Gruca, Prabhu S. Parimi, Alicia O'Brien, Leroy Dierker, and Ed Burkett. "Serine metabolism in human pregnancy." American Journal of Physiology-Endocrinology and Metabolism 284, no. 4 (April 1, 2003): E733—E740. http://dx.doi.org/10.1152/ajpendo.00167.2002.

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Serine plays an important role in intermediary metabolism as a source of one carbon pool for nucleotide biosynthesis, as a precursor for glycine and glucose, and as a contributor to cysteine biosynthesis. A unique serine-glycine cycling between the liver and the placenta has been demonstrated in the sheep fetus. We hypothesized that, because of serine's role in growth and development, significant changes in serine metabolism will occur in pregnancy with advancing gestation. The rate of appearance (Ra) of serine and its metabolism were quantified in healthy women longitudinally through pregnancy with a [2-15N13C]serine tracer. The contribution of serine N to urea and the rate of oxidation of serine were measured using the precursor-product relation. Plasma serine concentrations and serine Ra were lower in pregnant (P) women, in both early and late gestation, compared with nonpregnant (NP) women [plasma serine: NP, 113 ± 24.5; P early, 71.9 ± 6.2; P late, 68.5 ± 9.6 μmol/l; serine Ra: NP ( n = 7), 152.9 ± 42.8; P early ( n = 12), 123.7 ± 21.5; P late ( n = 8), 102.8 ± 18.2 μmol · kg−1 · h−1]. Serine contributed ∼6% to urea N and 15–20% to the plasma glycine pool, and oxidation of serine represented ∼8% of Ra. There was no significant difference between P and NP subjects. Glucose infusion, at 3 mg · kg−1 · min−1in P subjects, resulted in a decrease in serine Ra and an increase in oxidation. The decrease in serine turnover in pregnancy may represent a decrease in α-amino nitrogen turnover related to a decreased rate of branched-chain amino acid transamination and caused by pregnancy-related hormones aimed at nitrogen conservation and accretion.

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Parks, Lisa D., and Delon W. Barfuss. "Transepithelial transport and metabolism of glycine in S1, S2, and S3 cell types of the rabbit proximal tubule." American Journal of Physiology-Renal Physiology 283, no. 6 (December 1, 2002): F1208—F1215. http://dx.doi.org/10.1152/ajprenal.00021.2002.

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In the first of two sets of experiments, the lumen-to-cell and cell-to-bath transport rates for glycine were measured in the isolated-perfused medullary pars recta (S3 cells) of the rabbit proximal tubule at multiple luminal glycine concentrations (0–2.0 mM). The lumen-to-cell transport of glycine was saturated, which permitted the calculation of the transport maximum of disappearance rate of glycine from the lumen (pmol · min−1 · mm tubular length−1), K m (mM), and paracellular leak (pmol · min−1 · mm tubular length−1 · mM−1) values for this transport mechanism; these values were 4.3, 0.3, and 0.03, respectively. The cell-to-bath transport did not saturate but showed a linear relationship to cellular glycine concentration, 0.58 pmol · min−1 · mm tubular length−1 · mM−1. The second set of experiments characterized the transport rate, cellular accumulation, and metabolic rate of lumen-to-cell transported [3H]glycine in all segments (cell types) of the proximal tubule, pars convoluta (S1 cells), cortical pars recta (S2 cells), and medullary pars recta (S3 cells). These proximal tubular segments were isolated and perfused at a single glycine concentration of 11.2 μM. From the results of this study and previous work (Barfuss DW and Schafer JA. Am J Physiol 236: F149–F162, 1979), we conclude that the axial heterogeneity for glycine lumen-to-cell and cell-to-bath transport capacity extends to the medullary pars recta (S3 cells; S1 > S2 < S3 for lumen-to-cell transport and S1 > S2 > S3 for cell-to-bath transport). Also, we conclude that lumen-to-cell transported glycine can be metabolized and its metabolic rate displays axial heterogeneity (S1 > S2 > S3). The physiological significances of these transport and metabolic characteristics of the S3 cell type permits the medullary pars recta to effectively recover glycine from very low luminal glycine concentrations and makes glycine available for protective and maintenance metabolism of the medullary pars recta.

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Parimi, Prabhu S., Lourdes L. Gruca, and Satish C. Kalhan. "Metabolism of threonine in newborn infants." American Journal of Physiology-Endocrinology and Metabolism 289, no. 6 (December 2005): E981—E985. http://dx.doi.org/10.1152/ajpendo.00132.2005.

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Threonine kinetics, threonine oxidative pathway, and the relationship between threonine and whole body protein turnover were quantified in 10 healthy term infants during the first 48 h after birth. The kinetic data were obtained 6 h after the last feed (fasting) and in response to formula feeding, using [U-13C4,15N]threonine, [2H5]phenylalanine, and [15N]glycine tracers. The rate of carbon dioxide production (V̇co2) and13C enrichment of the expired CO2were measured to quantify the rate of oxidation of threonine. The rate of appearance (Ra) of threonine (136 ± 37 μmol·kg−1·h−1) was higher in newborn infants than that reported in adults. Formula feeding resulted in a significant decrease in threonine Ra( P < 0.05). A significant positive correlation was seen between phenylalanine Raand threonine Ra, both during fasting and after formula feeding ( r2= 0.65). In contrast to a 1:1 ratio of threonine and phenylalanine in mixed muscle protein, threonine Rarelative to phenylalanine Rawas 2.2 ± 0.4. The fractional rate of threonine flux oxidized was 20% during fasting and 26% ( P < 0.05) in response to nutrient administration. There was a significant correlation between plasma threonine concentration and threonine oxidation ( r2= 0.75). No measurable incorporation of threonine in plasma glycine was seen. These data suggest that threonine is exclusively degraded by the glycine-independent serine/threonine dehydratase pathway. A higher flux of threonine relative to phenylalanine indicates higher turnover of threonine enriched proteins.

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Carillo, Petronia, Gabriella Mastrolonardo, Francesco Nacca, Danila Parisi, Angelo Verlotta, and Amodio Fuggi. "Nitrogen metabolism in durum wheat under salinity: accumulation of proline and glycine betaine." Functional Plant Biology 35, no. 5 (2008): 412. http://dx.doi.org/10.1071/fp08108.

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We studied the effect of salinity on amino acid, proline and glycine betaine accumulation in leaves of different stages of development in durum wheat under high and low nitrogen supply. Our results suggest that protective compounds against salt stress are accumulated in all leaves. The major metabolites are glycine betaine, which preferentially accumulates in younger tissues, and proline, which is found predominantly in older tissues. Proline tended to accumulate early, at the onset of the stress, while glycine betaine accumulation was observed during prolonged stress. Nitrate reductase (NR) and glutamate synthase (GOGAT) are positively correlated with these compatible solutes: proline is associated with NR in the oldest leaves of high-nitrate plants and glycine betaine is associated with GOGAT in the youngest leaves of both low- and high-nitrate plants. In high-nitrate conditions proline accounts for more than 39% of the osmotic adjustment in the cytoplasmic compartments of old leaves. Its nitrogen-dependent accumulation may offer an important advantage in that it can be metabolised to allow reallocation of energy, carbon and nitrogen from the older leaves to the younger tissues. The contribution of glycine betaine is higher in young leaves and is independent of nitrogen nutrition.

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Nikandrov, V. N., and T. V. Balashevich. "Glycine receptors in nervous tissue and their functional role." Biomeditsinskaya Khimiya 60, no. 4 (2014): 403–15. http://dx.doi.org/10.18097/pbmc20146004403.

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The literature data on glycine metabolism in neural tissue, mitochondrial Gly-cleaving system, Gly-catching system in neural and glial cells are summarized. The peculiarities of localization and distribution of specific glycine receptors and binding-sites in nervous tissue of mammals are described. Four types of glycine-binding receptors are described: own specific glycine receptor (Gly-R), ionotropic receptor, which binds N-methyl-D-aspartate selectively (NMDA-R), and ionotropic receptors of g-aminobutyrate (GABA A -R, GABA С -R). The feutures of glycine effects in neuroglial cultures are discussed

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Elkins, Amy L., John G. Eley, Merrill C. Miller III, Iris H. Hall, Anup Sood, and Bernard Spielvogel. "Transepithelial Transport and Metabolism of Boronated Dipeptides Across Caco-2 and HCT-8 Cell Monolayers." Metal-Based Drugs 3, no. 6 (January 1, 1996): 277–86. http://dx.doi.org/10.1155/mbd.1996.277.

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Oral delivery of proteins and peptides as therapeutic agents is problematic due to their low bioavailability. This study examined the effect of boronation on the transepithelial transport and metabolism of three glycine-phenylalanine dipeptides in Caco-2 and HCT-8 cell monolayers. The three dipeptides exhibited passive transport characteristics in the monolayer systems. However, metabolism of the boronated dipeptides did occur, but to a lesser extent than the non-boronated glycine-phenylalanine dipeptide. The same metabolic scheme was seen in both cell monolayer system, but greater metabolism was seen in the HCT-8 cell monolayers.

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Hai, Yang, Arthur M. Huang, and Yi Tang. "Structure-guided function discovery of an NRPS-like glycine betaine reductase for choline biosynthesis in fungi." Proceedings of the National Academy of Sciences 116, no. 21 (May 6, 2019): 10348–53. http://dx.doi.org/10.1073/pnas.1903282116.

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Nonribosomal peptide synthetases (NRPSs) and NRPS-like enzymes have diverse functions in primary and secondary metabolisms. By using a structure-guided approach, we uncovered the function of a NRPS-like enzyme with unusual domain architecture, catalyzing two sequential two-electron reductions of glycine betaine to choline. Structural analysis based on the homology model suggests cation-π interactions as the major substrate specificity determinant, which was verified using substrate analogs and inhibitors. Bioinformatic analysis indicates this NRPS-like glycine betaine reductase is highly conserved and widespread in kingdom fungi. Genetic knockout experiments confirmed its role in choline biosynthesis and maintaining glycine betaine homeostasis in fungi. Our findings demonstrate that the oxidative choline-glycine betaine degradation pathway can operate in a fully reversible fashion and provide insight in understanding fungal choline metabolism. The use of an NRPS-like enzyme for reductive choline formation is energetically efficient compared with known pathways. Our discovery also underscores the capabilities of the structure-guided approach in assigning functions of uncharacterized multidomain proteins, which can potentially aid functional discovery of new enzymes by genome mining.

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Pérez-Torres, Israel, Blanca Ibarra, Elizabeth Soria-Castro, Rocío Torrico-Lavayen, Natalia Pavón, Eulises Diaz-Diaz, Pedro L. Flores, Oscar Infante, and Guadalupe Baños. "Effect of glycine on the cyclooxygenase pathway of the kidney arachidonic acid metabolism in a rat model of metabolic syndrome." Canadian Journal of Physiology and Pharmacology 89, no. 12 (December 2011): 899–910. http://dx.doi.org/10.1139/y11-086.

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The kidneys are organs that can be severely impaired by metabolic syndrome (MS). This is characterized by the association of various pathologies such as hypertension, dyslipidemia, and type-2 diabetes. Glycine, a nonessential amino acid, is known to possess various protective effects in the kidney, such as a decrease in the deterioration of renal function and a reduction of the damage caused by hypoxia. In a rat model of MS, the effect of glycine on the cyclooxygenase (COX) pathway of arachidonic acid (AA) metabolism was studied in isolated perfused kidney. MS was induced in Wistar rats by feeding them a 30% sucrose solution for 16 weeks. The addition of 1% glycine to their drinking water containing 30% sucrose, for 8 weeks, reduced high blood pressure, triglyceride levels, insulin concentration, homeostatis model assessment (HOMA) index, albuminuria, AA concentration in kidney homogenate, renal perfusion pressure, prostaglandin levels, PLA2expression, and COX isoform expression, compared with MS rats that did not receive the glycine supplement. Glycine receptor expression decreased significantly with MS, but glycine treatment increased it. The results suggest that in the MS model, 1% glycine treatment protects the kidney from damage provoked by the high sucrose consumption, by acting as an anti-inflammatory on the COX pathway of AA metabolism in kidney.

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Hankard, R. G., M. W. Haymond, and D. Darmaun. "Effect of glutamine on leucine metabolism in humans." American Journal of Physiology-Endocrinology and Metabolism 271, no. 4 (October 1, 1996): E748—E754. http://dx.doi.org/10.1152/ajpendo.1996.271.4.e748.

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The aim of this study was to determine whether the putative protein anabolic effect of glutamine 1) is mediated by increased protein synthesis or decreased protein breakdown and 2) is specific to glutamine. Seven healthy adults were administered 5-h intravenous infusions of L-[1-14C]leucine in the postabsorptive state while receiving in a randomized order an enteral infusion of saline on one day or L-glutamine (800 mumol.kg-1.h-1, equivalent to 0.11 g N/kg) on the other day. Seven additional subjects were studied using the same protocol except they received isonitrogenous infusion of glycine. The rates of leucine appearance (RaLeu), an index of protein degradation, leucine oxidation (OxLeu), and nonoxidative leucine disposal (NOLD), an index of protein synthesis, were measured using the 14C specific activity of plasma alpha-ketoisocaproate and the excretion rate of 14CO2 in breath. During glutamine infusion, plasma glutamine concentration doubled (673 +/- 66 vs. 1,184 +/- 37 microM, P < 0.05), whereas RaLeu did not change (122 +/- 9 vs. 122 +/- 7 mumol. kg-1.h-1), OxLeu decreased (19 +/- 2 vs. 11 +/- 1 mumol.kg-1.h-1, P < 0.01), and NOLD increased (103 +/- 8 vs. 111 +/- 6 mumol. kg-1.h-1, P < 0.01). During glycine infusion, plasma glycine increased 14-fold (268 +/- 62 vs. 3,806 +/- 546 microM, P < 0.01), but, in contrast to glutamine, RaLeu (124 +/- 6 vs. 110 +/- 4 mumol. kg-1.h-1, P = 0.02), OxLeu (17 +/- 1 vs. 14 +/- 1 mumol.kg-1.h-1, P = 0.03), and NOLD (106 +/- 5 vs. 96 +/- 3 mumol.kg-1.h-1, P < 0.05) all decreased. We conclude that glutamine enteral infusion may exert its protein anabolic effect by increasing protein synthesis, whereas an isonitrogenous amount of glycine merely decreases protein turnover with only a small anabolic effect resulting from a greater decrease in proteolysis than protein synthesis.

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Iwamoto, J., S. P. Yang, M. Yoshinaga, E. Krasney, and J. Krasney. "N omega-nitro-L-arginine influences cerebral metabolism in awake sheep." Journal of Applied Physiology 73, no. 6 (December 1, 1992): 2233–40. http://dx.doi.org/10.1152/jappl.1992.73.6.2233.

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Experiments were carried out on decerebrate cats to identify transsynaptic mediators of spontaneous postsynaptic inhibition of bulbar inspiratory and postinspiratory neurons. Somatic membrane potentials were recorded through the central micropipette of a coaxial multibarreled electrode. Blockers of type A gamma-aminobutyric acid (GABA-A) and glycine receptors were iontophoresed extracellularly from peripheral micropipettes surrounding the central pipette. Effective antagonism was demonstrated by iontophoresis of agonists with antagonists; application of strychnine antagonized the action of glycine but not GABA, and application of bicuculline antagonized the action of GABA but not glycine. In both types of neurons, iontophoresis of either antagonist depolarized the somatic membrane and increased input resistance throughout the respiratory cycle. Bicuculline preferentially depolarized the somatic membrane in both types of neurons during inactive phases. Strychnine increased the firing rate of inspiratory neurons during inspiration despite maintenance of somatic membrane potential at preiontophoresis levels. Tetrodotoxin reduced the effects of iontophoresed bicuculline and strychnine, suggesting that the action of the antagonists required presynaptic axonal conduction. The present results suggest that presynaptic release of both GABA and glycine contributes to tonic postsynaptic inhibition of bulbar respiratory neurons. GABA-A receptors appear to contribute to inhibition during inactive phases in inspiratory and postinspiratory neurons, whereas glycinergic mechanisms appear to contribute to inspiratory inhibition in inspiratory neurons.

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Choi, Changho, Pegah Askari, Elena Daoud, Kimmo Hatanpaa, Jack Raisanen, Cheryl Lewis, Michael Levy, et al. "NIMG-24. GLYCINE AND GLUTAMINE BY MR SPECTROSCOPY ARE IMAGING BIOMARKERS OF GLIOMA AGGRESSIVENESS." Neuro-Oncology 22, Supplement_2 (November 2020): ii152. http://dx.doi.org/10.1093/neuonc/noaa215.637.

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Abstract Cancers reprogram their metabolism and the resulting alterations in metabolite concentrations may be closely related to the clinical behavior of the tumors. We evaluated glycine, glutamine and 2-hydroxyglutarate (2HG) in 16 adult subjects with glioblastomas (9 male and 7 female; age 43-64 years, median 58) noninvasively using proton magnetic resonance spectroscopy and examined their association with the cell proliferation rate (MIB-1 labeling index) and overall survival. MRS was acquired using point-resolved spectroscopy (PRESS TE 97ms) at 3T. Metabolite levels were quantified with reference to water. The concentrations of glycine and glutamine were both positively correlated with MIB-1 (p=.002 and .0008 respectively). The sum of glycine and glutamine levels showed stronger association with MIB-1 (p< .0001). In the Kaplan-Meier overall survival analysis, the median survival was significantly shorter in patients with glycine levels higher than 2.3 mM than those with concentrations less than 2.3 mM. For glutamine, the patients with higher than 5.7 mM showed association with poor survival. The log-rank p value was substantially smaller in glutamine compared to glycine (p=.008 vs .04). The sum of glycine and glutamine levels showed stronger association with overall survival. 2HG level greater than 1 mM was associated with long survival, which was as expected since elevation of 2HG represents IDH mutant tumors and IDH mutation carries favorable prognosis. Given the association of low 2HG with poor survival, we tested metabolic ratios to 2HG, in which 2HG estimates < 1 mM were put as 1 mM. The glycine/2HG, glutamine/2HG, and (glycine+glutamine)/2HG showed stronger association with overall survival, compared to glycine, glutamine, and glycine+glutamine. Our data suggested that increased metabolism of glycine and glutamine is closely associated with rapid cell proliferation and poor clinical outcome, suggesting the metabolites as an MRS imaging biomarker of glioma aggressiveness.

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Lowry, M., D. E. Hall, and J. T. Brosnan. "Increased activity of renal glycine-cleavage-enzyme complex in metabolic acidosis." Biochemical Journal 231, no. 2 (October 15, 1985): 477–80. http://dx.doi.org/10.1042/bj2310477.

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Glycine is metabolized in isolated renal cortical tubules to stochiometric qualities of ammonia, CO2 and serine by the combined actions of the glycine-cleavage-enzyme complex and serine hydroxymethyltransferase. The rate of renal glycine metabolism by this route is increased in tubules from acidotic rats, but is not affected in vitro by decreasing the incubation pH from 7.4 to 7.1. Metabolic acidosis caused an increase in the renal activity of the glycine-cleavage-enzyme complex, but there were no changes in the activity of serine hydroxymethyltransferase or of methylenetetrahydrofolate dehydrogenase. This enzymic adaptation permits increased ammoniagenesis from glycine during acidosis. The physiological implications are discussed.

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Dreval, A. V., L. A. Marchenkova, R. S. Tshienin, B. I. Minchenko, G. A. Onoprienko, V. I. Shumsky, I. A. Komissarova, and Ya R. Narcissov. "Combination of hormone replacement therapy with natural metabolite preparations (glycine and limontar) in the treatment of menopausal syndrome." Problems of Endocrinology 45, no. 4 (August 15, 1999): 19–24. http://dx.doi.org/10.14341/probl11785.

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Clinical efficacy of two drugs, natural metabolites glycine and limontar, alone and in combination with substitute hormone therapy (SHT), is studied in patients with menopausal disorders. The clinical efficacy was assessed from the time course of neurovegetative, psychoemotional, and urogenital menopausal symptoms and from changes in mineral compactness of bone tissue and biochemical parameters of calcium-phosphorus metabolism and osseous metabolism. The results confirmed the efficacy of SHT in all types of climacteric disorders (neurovegetative, psychoemotional, urogenital, and in postmenopausal osteopenia). Combination of SHT with glycine and limontar did not affect the time course of the neurovegetative syndrome in general, but facilitated the arrest of arterial pressure differences and giddiness by estrogens. Moreover, glycine and limontar effectively relieve headaches. Combination of glycine with limontar is effective in asthenoneurotic syndrome in general and in individual psychoemotional symptoms: irritability, labile spirits, sleep disorders. In general asthenia and urogenital disorders glycine and limontar accelerated the clinical effect of SHT and in case of low spirits and decreased libido extend the spectrum of positive effects of SHT. The combination of glycine with limontar had no positive effect on the mineral compactness of bones. Combination of both drugs with SHT attenuated the process of bone formation, increased calcium excretion with the urine, and increased the hypocalcemic effect, and hence, they should not be prescribed in postmenopausal osteopenia or osteoporosis.

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Yang, Chi, Lu Ma, Donglai Xiao, Zhenghe Ying, Xiaoling Jiang, and Yanquan Lin. "Integration of ATAC-Seq and RNA-Seq Identifies Key Genes in Light-Induced Primordia Formation of Sparassis latifolia." International Journal of Molecular Sciences 21, no. 1 (December 26, 2019): 185. http://dx.doi.org/10.3390/ijms21010185.

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Light is an essential environmental factor for Sparassis latifolia primordia formation, but the molecular mechanism is still unclear. In this study, differential expression profiling of light-induced primordia formation (LIPF) was established by integrating the assay for transposase accessible chromatin by sequencing (ATAC-seq) and RNA-seq technology. The integrated results from the ATAC-seq and RNA-seq showed 13 down-regulated genes and 17 up-regulated genes in both the L vs. D and P vs. D groups, for both methods. According to the gene ontology (GO) annotation of these differentially expressed genes (DEGs), the top three biological process categories were cysteine biosynthetic process via cystathionine, vitamin B6 catabolic, and glycine metabolic; the top three molecular function categories were 5-methyltetrahydropteroyltriglutamate-homocysteine S-methyltransferase activity, glycine binding, and pyridoxal phosphate binding; cellular component categories were significantly enriched in the glycine cleavage complex. The KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis revealed that these genes were associated with vitamin B6 metabolism; selenocompound metabolism; cysteine and methionine metabolism; glycine, serine, and threonine metabolism; and glyoxylate and dicarboxylate metabolism pathways. The expression of most of the DEGs was validated by qRT-PCR. To the best of our knowledge, this study is the first integrative analysis of ATAC-seq and RNA-seq for macro-fungi. These results provided a new perspective on the understanding of key pathways and hub genes in LIPF in S. latifolia. It will be helpful in understanding the primary environmental response, and provides new information to the existing models of primordia formation in edible and medicinal fungi.

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Eulenburg, Volker, and Swen Hülsmann. "Synergistic Control of Transmitter Turnover at Glycinergic Synapses by GlyT1, GlyT2, and ASC-1." International Journal of Molecular Sciences 23, no. 5 (February 25, 2022): 2561. http://dx.doi.org/10.3390/ijms23052561.

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In addition to being involved in protein biosynthesis and metabolism, the amino acid glycine is the most important inhibitory neurotransmitter in caudal regions of the brain. These functions require a tight regulation of glycine concentration not only in the synaptic cleft, but also in various intracellular and extracellular compartments. This is achieved not only by confining the synthesis and degradation of glycine predominantly to the mitochondria, but also by the action of high-affinity large-capacity glycine transporters that mediate the transport of glycine across the membranes of presynaptic terminals or glial cells surrounding the synapses. Although most cells at glycine-dependent synapses express more than one transporter with high affinity for glycine, their synergistic functional interaction is only poorly understood. In this review, we summarize our current knowledge of the two high-affinity transporters for glycine, the sodium-dependent glycine transporters 1 (GlyT1; SLC6A9) and 2 (GlyT2; SLC6A5) and the alanine–serine–cysteine-1 transporter (Asc-1; SLC7A10).

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Kampen, K. "SP-0185 Role of serine/glycine metabolism in radioresistance." Radiotherapy and Oncology 170 (May 2022): S156. http://dx.doi.org/10.1016/s0167-8140(22)03900-7.

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Cegelski, Lynette, and Jacob Schaefer. "Glycine Metabolism in Intact Leaves byin Vivo13C and15N Labeling." Journal of Biological Chemistry 280, no. 47 (September 13, 2005): 39238–45. http://dx.doi.org/10.1074/jbc.m507053200.

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Pan, Sijing, Ming Fan, Zhangnan Liu, Xia Li, and Huijuan Wang. "Serine, glycine and one‑carbon metabolism in cancer (Review)." International Journal of Oncology 58, no. 2 (December 11, 2020): 158–70. http://dx.doi.org/10.3892/ijo.2020.5158.

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Waziri, Rafiq, Sankar Baruah, and Arnold D. Sherman. "Abnormal serine-glycine metabolism in the brains of schizophrenics." Schizophrenia Research 8, no. 3 (January 1993): 233–43. http://dx.doi.org/10.1016/0920-9964(93)90021-a.

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Schell, Michael J. "The N –methyl D–aspartate receptor glycine site and D–serine metabolism: an evolutionary perspective." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 359, no. 1446 (June 29, 2004): 943–64. http://dx.doi.org/10.1098/rstb.2003.1399.

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The N –methyl D–aspartate (NMDA) type of glutamate receptor requires two distinct agonists to operate. Glycine is assumed to be the endogenous ligand for the NMDA receptor glycine site, but this notion has been challenged by the discovery of high levels of endogenous D–serine in the mammalian forebrain. I have outlined an evolutionary framework for the appearance of a glycine site in animals and the metabolic events leading to high levels of D–serine in brain. Sequence alignments of the glycine–binding regions, along with the scant experimental data available, suggest that the properties of invertebrate NMDA receptor glycine sites are probably different from those in vertebrates. The synthesis of D–serine in brain is due to a pyridoxal–5'–phosphate (B 6 )–requiring serine racemase in glia. Although it remains unknown when serine racemase first evolved, data concerning the evolution of B 6 enzymes, along with the known occurrences of serine racemases in animals, point to D–serine synthesis arising around the divergence time of arthropods. D–Serine catabolism occurs via the ancient peroxisomal enzyme D–amino acid oxidase (DAO), whose ontogenetic expression in the hindbrain of mammals is delayed until the postnatal period and absent from the forebrain. The phylogeny of D–serine metabolism has relevance to our understanding of brain ontogeny, schizophrenia and neurotransmitter dynamics.

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Journal articles on the topic 'Glycine Metabolism'

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