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Artículos de revistas sobre el tema "Catalabolisme de la proline"

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Publicado: 25 de mayo de 2024

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1

Sarhan, S. y N. Seiler. "Proline and proline derivatives as anticonvulsants". General Pharmacology: The Vascular System 20, n.º 1 (enero de 1989): 53–60. http://dx.doi.org/10.1016/0306-3623(89)90060-8.

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2

Myung, Sunnie, Maren Pink, Mu-Hyun Baik y David E. Clemmer. "DL-Proline". Acta Crystallographica Section C Crystal Structure Communications 61, n.º 8 (23 de julio de 2005): o506—o508. http://dx.doi.org/10.1107/s0108270105021001.

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3

Opalka, Suzanne M., Ashley R. Longstreet y D. Tyler McQuade. "Continuous proline catalysis via leaching of solid proline". Beilstein Journal of Organic Chemistry 7 (14 de diciembre de 2011): 1671–79. http://dx.doi.org/10.3762/bjoc.7.197.

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Herein, we demonstrate that a homogeneous catalyst can be prepared continuously via reaction with a packed-bed of a catalyst precursor. Specifically, we perform continuous proline catalyzed α-aminoxylations using a packed-bed of L-proline. The system relies on a multistep sequence in which an aldehyde and thiourea additive are passed through a column of solid proline, presumably forming a soluble oxazolidinone intermediate. This transports a catalytic amount of proline from the packed-bed into the reactor coil for subsequent combination with a solution of nitrosobenzene, affording the desired optically active α-aminooxy alcohol after reduction. To our knowledge, this is the first example in which a homogeneous catalyst is produced continuously using a packed-bed. We predict that the method will not only be useful for other L-proline catalyzed reactions, but we also foresee that it could be used to produce other catalytic species in flow.

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4

Gruttadauria, Michelangelo, Francesco Giacalone y Renato Noto. "Supported proline and proline-derivatives as recyclable organocatalysts". Chemical Society Reviews 37, n.º 8 (2008): 1666. http://dx.doi.org/10.1039/b800704g.

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5

Csaba, G. y P. Kovács. "Imprinting Effects of Proline Containing Dipeptides (Proline-Glycine, Proline-Leucine, Proline-Valine and Their Retro Variants) in Tetrahymena. Evolutionary Conclusions". Bioscience Reports 17, n.º 6 (1 de diciembre de 1997): 537–42. http://dx.doi.org/10.1023/a:1027360207238.

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Proline-glycine, proline-leucine and proline-valine dipeptides and their retro variants were used in the experiments to study the effects of pretreatment (imprinting) in Tetrahymena, by investigating fluorescein isothiocyanate (FITC)-conjugated peptide binding. The protozoan organism could differentiate between the proline-dipeptides containing different partner amino-acids and between the dipeptides having the amino acids in reversed positions. The effect of imprinting was positive or negative and this was dependent on the type of the partner amino acid and on its position. Pro-Gly and Pro-Leu induced positive imprinting (elevated FITC-dipeptide binding) and Pro-Val induced negative imprinting (decrease of FITC-peptide binding). There was positive imprinting induction in two cases for the retro FITC-peptide and in one case for the FITC-conjugate of the imprinter peptide itself. The highest positive imprinting (almost 60% increase) was induced by Pro-Gly for FITC-Gly-Pro. Considering earlier—chemotaxis—experiments, the results of the present—binding—studies run parallel with the physiological effects. The experiments call attention to the sharp differentiating ability of small peptides at a unicellular level, that could have some role in the selection of molecules for hormone formation, during evolution.

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6

Rutella, Giuseppina Sefora, Lisa Solieri, Serena Martini y Davide Tagliazucchi. "Release of the Antihypertensive Tripeptides Valine-Proline-Proline and Isoleucine-Proline-Proline from Bovine Milk Caseins during in Vitro Gastrointestinal Digestion". Journal of Agricultural and Food Chemistry 64, n.º 45 (7 de noviembre de 2016): 8509–15. http://dx.doi.org/10.1021/acs.jafc.6b03271.

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7

Medha, Sadhna Sharma y Monika Sharma. "Proline-Glutamate/Proline-Proline-Glutamate (PE/PPE) proteins of Mycobacterium tuberculosis: The multifaceted immune-modulators". Acta Tropica 222 (octubre de 2021): 106035. http://dx.doi.org/10.1016/j.actatropica.2021.106035.

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8

Mandalapu, Dhanaraju. "l-Proline and d-Proline (Chiral Amino Acid Catalysts)". Synlett 26, n.º 05 (19 de febrero de 2015): 707–8. http://dx.doi.org/10.1055/s-0034-1380270.

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9

Tritsch, Denis, Hiba Mawlawi y Jean-François Biellmann. "Mechanism-based inhibition of proline dehydrogenase by proline analogues". Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology 1202, n.º 1 (septiembre de 1993): 77–81. http://dx.doi.org/10.1016/0167-4838(93)90065-y.

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10

Hill, JeffW y EdwinM Nemoto. "N -acetyl proline-glycine-proline: implications for neurological disorders". Neural Regeneration Research 11, n.º 6 (2016): 0. http://dx.doi.org/10.4103/1673-5374.184478.

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11

Long, Mengfei, Meijuan Xu, Zhenfeng Ma, Xuewei Pan, Jiajia You, Mengkai Hu, Yu Shao, Taowei Yang, Xian Zhang y Zhiming Rao. "Significantly enhancing production of trans-4-hydroxy-l-proline by integrated system engineering in Escherichia coli". Science Advances 6, n.º 21 (mayo de 2020): eaba2383. http://dx.doi.org/10.1126/sciadv.aba2383.

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Trans-4-hydroxy-l-proline is produced by trans-proline-4-hydroxylase with l-proline through glucose fermentation. Here, we designed a thorough “from A to Z” strategy to significantly improve trans-4-hydroxy-l-proline production. Through rare codon selected evolution, Escherichia coli M1 produced 18.2 g L−1l-proline. Metabolically engineered M6 with the deletion of putA, proP, putP, and aceA, and proB mutation focused carbon flux to l-proline and released its feedback inhibition. It produced 15.7 g L−1trans-4-hydroxy-l-proline with 10 g L−1l-proline retained. Furthermore, a tunable circuit based on quorum sensing attenuated l-proline hydroxylation flux, resulting in 43.2 g L−1trans-4-hydroxy-l-proline with 4.3 g L−1l-proline retained. Finally, rationally designed l-proline hydroxylase gave 54.8 g L−1trans-4-hydroxy-l-proline in 60 hours almost without l-proline remaining—the highest production to date. The de novo engineering carbon flux through rare codon selected evolution, dynamic precursor modulation, and metabolic engineering provides a good technological platform for efficient hydroxyl amino acid synthesis.

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12

Falcioni, Francesco, Lars M. Blank, Oliver Frick, Andreas Karau, Bruno Bühler y Andreas Schmid. "Proline Availability Regulates Proline-4-Hydroxylase Synthesis and Substrate Uptake in Proline-Hydroxylating Recombinant Escherichia coli". Applied and Environmental Microbiology 79, n.º 9 (1 de marzo de 2013): 3091–100. http://dx.doi.org/10.1128/aem.03640-12.

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ABSTRACTMicrobial physiology plays a crucial role in whole-cell biotransformation, especially for redox reactions that depend on carbon and energy metabolism. In this study, regio- and enantio-selective proline hydroxylation with recombinantEscherichia coliexpressing proline-4-hydroxylase (P4H) was investigated with respect to its interconnectivity to microbial physiology and metabolism. P4H production was found to depend on extracellular proline availability and on codon usage. Medium supplementation with proline did not alterp4hmRNA levels, indicating that P4H production depends on the availability of charged prolyl-tRNAs. Increasing the intracellular levels of soluble P4H did not result in an increase in resting cell activities above a certain threshold (depending on growth and assay temperature). Activities up to 5-fold higher were reached with permeabilized cells, confirming that host physiology and not the intracellular level of active P4H determines the achievable whole-cell proline hydroxylation activity. Metabolic flux analysis revealed that tricarboxylic acid cycle fluxes in growing biocatalytically active cells were significantly higher than proline hydroxylation rates. Remarkably, a catalysis-induced reduction of substrate uptake was observed, which correlated with reduced transcription ofputAandputP, encoding proline dehydrogenase and the major proline transporter, respectively. These results provide evidence for a strong interference of catalytic activity with the regulation of proline uptake and metabolism. In terms of whole-cell biocatalyst efficiency, proline uptake and competition of P4H with proline catabolism are considered the most critical factors.

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13

Lee, Yi-Chien, Patricia L. Jackson, Michael J. Jablonsky, Donald D. Muccio, Roswell R. Pfister, Jeffrey L. Haddox, Charnell I. Sommers, G. M. Anantharamaiah y Manjula Chaddha. "NMR conformational analysis ofcis andtrans proline isomers in the neutrophil chemoattractant, N-acetyl-proline-glycine-proline". Biopolymers 58, n.º 6 (2001): 548–61. http://dx.doi.org/10.1002/1097-0282(200105)58:6<548::aid-bip1030>3.0.co;2-b.

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14

Opsahl, W. P. y L. A. Ehrhart. "Compartmentalization of proline pools and apparent rates of collagen and non-collagen protein synthesis in arterial smooth μscle cells in culture". Biochemical Journal 243, n.º 1 (1 de abril de 1987): 137–44. http://dx.doi.org/10.1042/bj2430137.

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Rates of collagen and non-collagen protein synthesis in rabbit arterial smooth muscle cells (SMC) were determined by using the specific (radio)activity of [3H]proline in the extracellular, intracellular, and prolyl-tRNA pools. The intracellular free proline specific activity was only 25% of the extracellular value in cultures incubated for 12 h in 0.25 mM-proline. The specific activity of prolyl-tRNA was less than 10% of the extracellular specific activity. Increasing the extracellular proline concentration 10-fold (to 2.5 mM), while keeping the extracellular specific activity of proline constant, resulted in equilibration of the specific activities of intracellular and extracellular free proline, but the specific activity of prolyl-tRNA remained at less than 10% of the extracellular specific activity. Therefore, calculated rates of collagen and non-collagen protein synthesis were greatly underestimated using the intracellular or extracellular specific activity of proline. SMC were also incubated with 0.1 mM-[14C]ornithine in 0.25 nM or 2.5 mM non-labelled proline to examine synthesis de novo of proline and prolyl-tRNA from ornithine. In SMC cultures containing 0.25 mM unlabelled proline, the specific activity of intracellular ornithine was approx. 45% of the extracellular specific activity, due to the production of unlabelled ornithine. The specific activity of ornithine-derived intracellular free proline in SMC incubated with 2.5 mM-proline was significantly lower than in SMC incubated in 0.25 mM-proline, due to the influx of unlabelled proline. However, a corresponding difference in the specific activity of [14C]prolyl-tRNA between SMC in 0.25 mM- or 2.5 mM-proline was not observed. Ornithine-derived [14C]proline was incorporated into proteins in a manner different from that of exogenously added radiolabelled proline. A much higher proportion of the proline synthesized de novo was channelled into collagen synthesis relative to total protein synthesis. Together, these results show that intracellular proline pools are highly compartmentalized in arterial SMC. They also suggest that proline synthesized from ornithine may enter a prolyl-tRNA pool separate from that of proline entering from the extracellular medium.

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15

Liu, Ning, Ying Yang, Xuemeng Si, Hai Jia, Yunchang Zhang, Da Jiang, Zhaolai Dai y Zhenlong Wu. "L-Proline Activates Mammalian Target of Rapamycin Complex 1 and Modulates Redox Environment in Porcine Trophectoderm Cells". Biomolecules 11, n.º 5 (17 de mayo de 2021): 742. http://dx.doi.org/10.3390/biom11050742.

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L-proline (proline) is a key regulator of embryogenesis, placental development, and fetal growth. However, the underlying mechanisms that support the beneficial effects of proline are largely unknown. This study used porcine trophectoderm cell line 2 (pTr2) to investigate the underlying mechanisms of proline in cell proliferation and redox homeostasis. Cells were cultured in the presence of 0, 0.25, 0.50, or 1.0 mmol/L proline for an indicated time. The results showed that 0.5 and 1.0 mmol/L proline enhanced cell viability. These effects of proline (0.5 mmol/L) were accompanied by the enhanced protein abundance of p-mTORC1, p-p70S6K, p-S6, and p-4E-BP1. Additionally, proline dose-dependently enhanced the mRNA expression of proline transporters [solute carrier family (SLC) 6A20, SLC36A1, SLC36A2, SLC38A1, and SLC38A2], elevated proline concentration, and protein abundance of proline dehydrogenase (PRODH). Furthermore, proline addition (0.25 or 0.5 mmol/L) resulted in lower abundance of p-AMPKα when compared with a control. Of note, proline resulted in lower reactive oxygen species (ROS) level, upregulated mRNA expression of the catalytic subunit of glutamate–cysteine ligase (GCLC) and glutathione synthetase (GSS), as well as enhanced total (T)-GSH and GSH concentration when compared with a control. These data indicated that proline activates themTORC1 signaling and modulates the intracellular redox environment via enhancing proline transport.

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16

Schwan, William R., Keith J. Wetzel, Timothy S. Gomez, Melissa A. Stiles, Brian D. Beitlich y Sandra Grunwald. "Low-proline environments impair growth, proline transport and in vivo survival of Staphylococcus aureus strain-specific putP mutants". Microbiology 150, n.º 4 (1 de abril de 2004): 1055–61. http://dx.doi.org/10.1099/mic.0.26710-0.

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Staphylococcus aureus is a common cause of disease in humans, particularly in hospitalized patients. This species needs to import several amino acids to survive, including proline. Previously, it was shown that an insertion mutation in the high-affinity proline uptake gene putP in strain RN6390 affected proline uptake by the bacteria as well as reducing their ability to survive in vivo. To further delineate the effect of the putP mutation on growth of S. aureus strain RN6390, a proline uptake assay that spanned less than 1 min was done to measure transport. An eightfold difference in proline levels was observed between the wild-type strain and the high-affinity proline transport mutant strain after 15 s, indicating that the defect was only in proline transport and not a combination of proline transport, metabolism and accumulation that would have been assessed with longer assays. A putP mutant of S. aureus strain RN4220 was then grown in minimal medium with different concentrations of proline. When compared to the wild-type strain, the putP mutant strain was significantly growth impaired when the level of proline was decreased to 1·74 μM. An assessment of proline concentrations in mouse livers and spleens showed proline concentrations of 7·5 μmol per spleen and 88·4 μmol per liver. To verify that the effects on proline transport and bacterial survival were indeed caused solely by a mutation in putP, the putP mutation was complemented by cloning a full-length putP gene on a plasmid that replicates in S. aureus. Complementation of the putP mutant strains restored proline transport, in vitro growth in low-proline medium, and in vivo survival within mice. These results show that the mutation in putP led to attenuated growth in low-proline media and by corollary low-proline murine organ tissues due to less efficient transport of proline into the bacteria.

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17

SUZUKI, Yuzuru. "The proline rule". Proceedings of the Japan Academy. Ser. B: Physical and Biological Sciences 75, n.º 6 (1999): 133–37. http://dx.doi.org/10.2183/pjab.75.133.

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18

&NA;. "Lysine-proline derivatives". Inpharma Weekly &NA;, n.º 837 (mayo de 1992): 12. http://dx.doi.org/10.2165/00128413-199208370-00018.

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19

Alderton, Gemma K. "Targeting proline metabolism?" Nature Reviews Cancer 16, n.º 11 (24 de octubre de 2016): 678. http://dx.doi.org/10.1038/nrc.2016.119.

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20

Gough, N. R. "Proline Promotes Virulence". Science Signaling 3, n.º 106 (26 de enero de 2010): ec31-ec31. http://dx.doi.org/10.1126/scisignal.3106ec31.

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21

Padmanabhan, S., S. Suresh y M. Vijayan. "DL-Proline Monohydrate". Acta Crystallographica Section C Crystal Structure Communications 51, n.º 10 (15 de octubre de 1995): 2098–100. http://dx.doi.org/10.1107/s0108270195003465.

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22

Cunningham, Damian F. y Brendan O'Connor. "Proline specific peptidases". Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology 1343, n.º 2 (diciembre de 1997): 160–86. http://dx.doi.org/10.1016/s0167-4838(97)00134-9.

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23

Coatnoan, Nicolas, Armand Berneman, Nathalie Chamond y Paola Minoprio. "Proline racemases: insights into Trypanosoma cruzi peptides containing D-proline". Memórias do Instituto Oswaldo Cruz 104, suppl 1 (julio de 2009): 295–300. http://dx.doi.org/10.1590/s0074-02762009000900039.

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24

Pétry, Nicolas, Hafid Benakki, Eric Clot, Pascal Retailleau, Farhate Guenoun, Fatima Asserar, Chakib Sekkat, Thomas-Xavier Métro, Jean Martinez y Frédéric Lamaty. "A mechanochemical approach to access the proline–proline diketopiperazine framework". Beilstein Journal of Organic Chemistry 13 (19 de octubre de 2017): 2169–78. http://dx.doi.org/10.3762/bjoc.13.217.

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Ball milling was exploited to prepare a substituted proline building block by mechanochemical nucleophilic substitution. Subsequently, the mechanocoupling of hindered proline amino acid derivatives was developed to provide proline–proline dipeptides under solvent-free conditions. A deprotection–cyclization sequence yielded the corresponding diketopiperazines that were obtained with a high stereoselectivity which could be explained by DFT calculations. Using this method, an enantiopure disubstituted Pro–Pro diketopiperazine was synthesized in 4 steps, making 5 new bonds using a ball mill.

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25

Carlson, Kristine L., Stephen L. Lowe, Mark R. Hoffmann y Kathryn A. Thomasson. "Theoretical UV Circular Dichroism of Cyclo(l-Proline-l-Proline)". Journal of Physical Chemistry A 110, n.º 17 (mayo de 2006): 5965. http://dx.doi.org/10.1021/jp061761c.

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26

Hasegawa, H. y S. Mori. "Non-proline-accumulating rice mutants resistant to hydroxy-L-proline". Theoretical and Applied Genetics 72, n.º 2 (1986): 226–30. http://dx.doi.org/10.1007/bf00266996.

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27

Natarajan, Sathish Kumar y Donald F. Becker. "Importance of Proline Dehydrogenase in Proline Protection against Oxidative Stress". Free Radical Biology and Medicine 49 (enero de 2010): S191—S192. http://dx.doi.org/10.1016/j.freeradbiomed.2010.10.551.

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28

Jackson, Patricia. "Cigarette smoke enhances chemotaxis via acetylation of proline-glycine-proline". Frontiers in Bioscience E4, n.º 7 (2012): 2402–9. http://dx.doi.org/10.2741/e552.

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29

Carlson, Kristine L., Stephen L. Lowe, Mark R. Hoffmann y Kathryn A. Thomasson. "Theoretical UV Circular Dichroism of Cyclo(l-Proline-l-Proline)". Journal of Physical Chemistry A 110, n.º 5 (febrero de 2006): 1925–33. http://dx.doi.org/10.1021/jp052924k.

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30

Morishima-Kawashima, Maho, Masato Hasegawa, Koji Takio, Masami Suzuki, Hirotaka Yoshida, Koiti Titani y Yasuo Ihara. "Proline-directed and Non-proline-directed Phosphorylation of PHF-tau". Journal of Biological Chemistry 270, n.º 2 (13 de enero de 1995): 823–29. http://dx.doi.org/10.1074/jbc.270.2.823.

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31

Harrison, Alex G. y Alex B. Young. "Fragmentation reactions of deprotonated peptides containing proline. The proline effect". Journal of Mass Spectrometry 40, n.º 9 (septiembre de 2005): 1173–86. http://dx.doi.org/10.1002/jms.891.

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32

Kuo, C. G., H. M. Chen y L. H. Ma. "Effect of High Temperature on Proline Content in Tomato Floral Buds and Leaves". Journal of the American Society for Horticultural Science 111, n.º 5 (septiembre de 1986): 746–50. http://dx.doi.org/10.21273/jashs.111.5.746.

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Abstract The proline contents of anthers, pollen, pistils, and leaves were examined in several tomato (Lycopersicon esculentum Mill.) cultivars under different temperature conditions. The proline content in anthers increased with advancing development of floral buds to a maximum at anthesis. The pistil contained less proline than the anthers and did not accumulate proline with advancement of floral bud development in most cultivars. High temperature reduced proline content in anthers regardless of the stages of floral bud development. It also tended to reduce proline content in pistils of later floral bud stage. The proline content of the leaves was lower than that of anthers or pistils; however, high temperature increased the proline level in the leaves. Pollen collected from the hot-season planting contained less proline than that collected from the cool-season planting. The addition of proline to germination medium enhanced pollen germination rate and increased pollen resistance to heat. These results suggest that the low proline accumulation in anthers and pollen at high temperature may be the result of the high accumulation in the leaves. Also, high proline content in anthers may be necessary to confer heat resistance to pollen germinating at high temperatures.

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33

Cicero, A. F. G., F. Aubin, V. Azais-Braesco y C. Borghi. "Do the Lactotripeptides Isoleucine-Proline-Proline and Valine-Proline-Proline Reduce Systolic Blood Pressure in European Subjects? A Meta-Analysis of Randomized Controlled Trials". American Journal of Hypertension 26, n.º 3 (7 de enero de 2013): 442–49. http://dx.doi.org/10.1093/ajh/hps044.

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34

Lehman, McKenzie K., Natalie A. Sturd, Fareha Razvi, Dianne L. Wellems, Steven D. Carson y Paul D. Fey. "Proline transporters ProT and PutP are required for Staphylococcus aureus infection". PLOS Pathogens 19, n.º 1 (18 de enero de 2023): e1011098. http://dx.doi.org/10.1371/journal.ppat.1011098.

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Proline acquired via specific transporters can serve as a proteinogenic substrate, carbon and nitrogen source, or osmolyte. Previous reports have documented that Staphylococcus aureus, a major community and nosocomial pathogen, encodes at least four proline transporters, PutP, OpuC, OpuD, and ProP. A combination of genetic approaches and 3H-proline transport assays reveal that a previously unrecognized transporter, ProT, in addition to PutP, are the major proline transporters in S. aureus. Complementation experiments using constitutively expressed non-cognate promoters found that proline transport via OpuD, OpuC, and ProP is minimal. Both proline biosynthesis from arginine and proline transport via ProT are critical for growth when S. aureus is grown under conditions of high salinity. Further, proline transport mediated by ProT or PutP are required for growth in media with and without glucose, indicating both transporters function to acquire proline for proteinogenic purposes in addition to acquisition of proline as a carbon/nitrogen source. Lastly, inactivation of proT and putP resulted in a significant reduction (5 log10) of bacterial burden in murine skin-and-soft tissue infection and bacteremia models, suggesting that proline transport is required to establish a S. aureus infection.

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35

Deutch, Charles E., James M. Hasler, Rochelle M. Houston, Manish Sharma y Valerie J. Stone. "Nonspecific inhibition of proline dehydrogenase synthesis in Escherichia coli during osmotic stress". Canadian Journal of Microbiology 35, n.º 8 (1 de agosto de 1989): 779–85. http://dx.doi.org/10.1139/m89-130.

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L-Proline, which is accumulated by Escherichia coli during growth in media of high osmolality, also induces the synthesis of the enzyme degrading it to glutamate. To determine if proline catabolism is inhibited during osmotic stress, proline utilization and the formation of proline dehydrogenase were examined in varying concentrations of NaCl and sucrose. Although the specific growth rate of E. coli with proline as the sole nitrogen source diminished as the solute osmolality increased, a comparable reduction in growth rate occurred with ammonium as the primary nitrogen source. Proline catabolism, as measured in whole cells by the conversion of [14C]proline to [14C]glutamate, was only slightly inhibited by solute osmolalities up to 1.0 osmol/kg; more than 50% of the initial activity was still found at 2.0 osmol/kg. By contrast, the specific activity of proline dehydrogenase in bacteria grown in the presence of added solutes decreased to less than 20% of the control level. This reduction was related to a lower rate of synthesis, but was independent of genes currently known to be involved in osmoregulation or proline metabolism. The specific activities of tryptophanase, β-galactosidase, and histidinol dehydrogenase were also reduced under similar growth conditions. These results indicate that while proline catabolism is not directly inhibited by high solute concentrations, prolonged exposure to osmotic stress leads to its reduction as part of a more general metabolic response.Key words: osmotic stress, proline, proline catabolism, proline dehydrogenase, PutA protein.

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36

Bashir, Abdallah, Tamara Hoffmann, Bettina Kempf, Xiulan Xie, Sander H. J. Smits y Erhard Bremer. "Plant-derived compatible solutes proline betaine and betonicine confer enhanced osmotic and temperature stress tolerance to Bacillus subtilis". Microbiology 160, n.º 10 (1 de octubre de 2014): 2283–94. http://dx.doi.org/10.1099/mic.0.079665-0.

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l-Proline is a widely used compatible solute and is employed by Bacillus subtilis, through both synthesis and uptake, as an osmostress protectant. Here, we assessed the stress-protective potential of the plant-derived l-proline derivatives N-methyl-l-proline, l-proline betaine (stachydrine), trans-4-l-hydroxproline and trans-4-hydroxy-l-proline betaine (betonicine) for cells challenged by high salinity or extremes in growth temperature. l-Proline betaine and betonicine conferred salt stress protection, but trans-4-l-hydroxyproline and N-methyl-l-proline was unable to do so. Except for l-proline, none of these compounds served as a nutrient for B. subtilis. l-Proline betaine was a considerably better osmostress protectant than betonicine, and its import strongly reduced the l-proline pool produced by B. subtilis under osmotic stress conditions, whereas a supply of betonicine affected the l-proline pool only modestly. Both compounds downregulated the transcription of the osmotically inducible opuA operon, albeit to different extents. Mutant studies revealed that l-proline betaine was taken up via the ATP-binding cassette transporters OpuA and OpuC, and the betaine-choline-carnitine-transporter-type carrier OpuD; betonicine was imported only through OpuA and OpuC. l-Proline betaine and betonicine also served as temperature stress protectants. A striking difference between these chemically closely related compounds was observed: l-proline betaine was an excellent cold stress protectant, but did not provide heat stress protection, whereas the reverse was true for betonicine. Both compounds were primarily imported in temperature-challenged cells via the high-capacity OpuA transporter. We developed an in silico model for the OpuAC–betonicine complex based on the crystal structure of the OpuAC solute receptor complexed with l-proline betaine.

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37

Gavelienė, V., L. Pakalniškytė y L. Novickienė. "Regulation of proline and ethylene levels in rape seedlings for freezing tolerance". Open Life Sciences 9, n.º 11 (1 de noviembre de 2014): 1099–107. http://dx.doi.org/10.2478/s11535-014-0340-z.

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AbstractThis study was aimed to investigate the possibility of regulating free proline content and ethylene production in the resistant to abiotic stress cv. ‘Hornet H’ and the tolerant to stress cv. ‘Sunday’ of winter rapeseed seedlings by pretreatment with exogenous L-proline and L-glutamine in non-acclimated and cold-acclimated seedlings in relation to freezing tolerance. The ratio of proline content in acclimated (at 4°C) versus non-acclimated (18°C) ‘Hornet H’ seedlings increased 2.12-fold and in ‘Sunday’ seedlings 1.95-fold. Exogenously applied, proline and glutamine produced a positive effect on free proline content in both cold-acclimated and non-acclimated seedlings. At a temperature of -1°C the proline content significantly increased in non-acclimated and especially in cold-acclimated seedlings. At an intensified freezing temperature (−3°C, −5°C, −7°C), the proline content decreased in comparison with that at −1°C, but glutamine, especially proline, in cold-acclimated seedlings takes part in free proline level increase and in seedlings’ resistance to freezing. Ethylene production increased in cold-acclimated conditions and under the effect of exogenous proline and glutamine. In freezing conditions, ethylene production decreased, but in cold-acclimated seedlings and under pretreatment of proline and glutamine the ethylene synthesis was intensive. Thus, free proline content and ethylene production increase in cold-acclimated winter rapeseed seedlings and under pretreatment with glutamine and especially with proline. Free proline is involved in the response to cold stress, and its level may be an indicator of cold-hardening and freezing tolerance, but the role of ethylene in the regulation of cold tolerance remains not quite clear.

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Wuerzner, Grégoire, Séverine Peyrard, Anne Blanchard, Florent Lalanne y Michel Azizi. "The lactotripeptides isoleucine-proline-proline and valine-proline-proline do not inhibit the N-terminal or C-terminal angiotensin converting enzyme active sites in humans". Journal of Hypertension 27, n.º 7 (julio de 2009): 1404–9. http://dx.doi.org/10.1097/hjh.0b013e32832b4759.

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39

Šilhánková, Alexandra, Karel Šindelář, Karel Dobrovský, Ivan Krejčí, Jarmila Hodková y Zdeněk Polívka. "Synthesis of New L-Proline Amides with Anticonvulsive Effect". Collection of Czechoslovak Chemical Communications 61, n.º 7 (1996): 1085–92. http://dx.doi.org/10.1135/cccc19961085.

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Series of heterocyclic L-proline amides were prepared from BOC-L-proline and heterocyclic amines (mostly substituted piperazines and morpholines) via active ester with hydroxysuccinimide. 4-(4-Fluorobenzoyl)piperidine afforded L-proline 4-(4-(4-(4-fluorobenzoyl)piperidin-1-yl)benzoyl)piperidine (7b) simultaneously with expected L-proline 4-(4-fluorobenzoyl)piperidide (7a). D-Proline N-(3-(4-(3-chlorophenyl)piperazin-1-yl)propyl)amide (2) was prepared starting from D-proline. The amides were tested by methods of biochemical and behavioural pharmacology.

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40

Guo, Ling y Chuanyue Wu. "Mitochondrial dynamics links PINCH-1 signaling to proline metabolic reprogramming and tumor growth". Cell Stress 5, n.º 2 (8 de febrero de 2021): 23–25. http://dx.doi.org/10.15698/cst2021.02.241http://www.cell-stress.com/researcharticles/2020a-guo-cell-stress/.

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Proline metabolism is critical for cellular response to microenvironmental stress in living organisms across different kingdoms, ranging from bacteria, plants to animals. In bacteria and plants, proline is known to accrue in response to osmotic and other stresses. In higher organisms such as human, proline metabolism plays important roles in physiology as well as pathological processes including cancer. The importance of proline metabolism in physiology and diseases lies in the fact that the products of proline metabolism are intimately involved in essential cellular processes including protein synthesis, energy production and redox signaling. A surge of protein synthesis in fast proliferating cancer cells, for example, results in markedly increased demand for proline. Proline synthesis is frequently unable to meet the demand in fast proliferating cancer cells. The inadequacy of proline or “proline vulnerability” in cancer may provide an opportunity for therapeutic control of cancer progression. To this end, it is important to understand the signaling mechanism through which proline synthesis is regulated. In a recent study (Guo et al., Nat Commun 11(1):4913, doi: 10.1038/s41467-020-18753-6), we have identified PINCH-1, a component of cell-extracellular matrix (ECM) adhesions, as an important regulator of proline synthesis and cancer progression.

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41

Schwan, William R. "Proline Transport and Growth Changes in Proline Transport Mutants of Staphylococcus aureus". Microorganisms 10, n.º 10 (21 de septiembre de 2022): 1888. http://dx.doi.org/10.3390/microorganisms10101888.

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Staphylococcus aureus is a major cause of skin/soft tissue infections and more serious infections in humans. The species usually requires the importation of proline to be able to survive. Previous work has shown that single mutations in genes that encode for proline transporters affect the ability of S. aureus to survive in vitro and in vivo. To better understand proline transport in S. aureus, double and triple gene mutant strains were created that targeted the opuD, proP, and putP genes. Single gene mutants had some effect on proline transport, whereas double mutants exhibited significantly lower proline transport. An opuD prop putP triple gene mutant displayed the lowest proline transport under low- and high-affinity conditions. To assess growth differences caused by the mutations, the same mutants were grown in brain heart infusion (BHI) broth and defined staphylococcal medium (DSM) with various concentrations of proline. The triple mutant did not grow in DSM with a low concentration of proline and grew poorly in both DSM with a high proline concentration and BHI broth. These results show that S. aureus has multiple mechanisms to import proline into the cell and knocking out three of the main proline transporters significantly hinders S. aureus growth.

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42

Kijowska-Oberc, Joanna, Mikołaj K. Wawrzyniak, Liliana Ciszewska y Ewelina Ratajczak. "Evaluation of P5CS and ProDH activity in Paulownia tomentosa (Steud.) as an indicator of oxidative changes induced by drought stress". PeerJ 12 (25 de enero de 2024): e16697. http://dx.doi.org/10.7717/peerj.16697.

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The aim of the study was to investigate changes in proline metabolism in seedlings of tree species during drought stress. One month old Paulownia tomentosa seedlings were exposed to moisture conditions at various levels (irrigation at 100, 75, 50 and 25% of field capacity), and then the material (leaves and roots) was collected three times at 10-day intervals. The activity of enzymes involved in proline metabolism was closely related to drought severity; however, proline content was not directly impacted. The activity of pyrroline-5-carboxylate synthetase (P5CS), which catalyzes proline biosynthesis, increased in response to hydrogen peroxide accumulation, which was correlated with soil moisture. In contrast, the activity of proline dehydrogenase (ProDH), which catalyzes proline catabolism, decreased. Compared to proline, the activity of these enzymes may be a more reliable biochemical marker of stress-induced oxidative changes. The content of proline is dependent on numerous additional factors, i.e., its degradation is an important alternative energy source. Moreover, we noted tissue-specific differences in this species, in which roots appeared to be proline biosynthesis sites and leaves appeared to be proline catabolism sites. Further research is needed to examine a broader view of proline metabolism as a cycle regulated by multiple mechanisms and differences between species.

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43

Emmerson, Katherine S. y James M. Phang. "Hydrolysis of Proline Dipeptides Completely Fulfills the Proline Requirement in a Proline-Auxotrophic Chinese Hamster Ovary Cell Line". Journal of Nutrition 123, n.º 5 (1 de mayo de 1993): 909–14. http://dx.doi.org/10.1093/jn/123.5.909.

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44

Nagamalleswari, Gampa y M. S. Umashankar. "Derivatization of Proline for the Enantiomeric Separation and Estimation of D-Proline in L-Proline by NP-HPLC". INTERNATIONAL JOURNAL OF PHARMACEUTICAL QUALITY ASSURANCE 14, n.º 03 (25 de septiembre de 2023): 767–70. http://dx.doi.org/10.25258/ijpqa.14.3.52.

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The core object of this exertion is to progress and validate a modest, competent and explicit method for the exodus of D and L isomers of proline in a racemic mixture and limit the content of D-Proline in commercial L-Proline. This has been technologically advanced in a chiral method using normal phase HPLC on CHIRALPAK-IA (250X4.6 mm) 5 μ column. This progress advanced with polar mobile phase ethanol encompassing modifier/additive TFA in 0.1% concentration. Due to the chromophore’s deficiency in proline, proline’s derivatization has been done using fluorescent reagent NBD-Cl. After derivatization, proline has made UV detectable at 465 nm. Within run time of 20 minutes, D and L isomers of proline were eluted at 6.72 and 9.22 minutes, respectively. The technologically advanced method was validated as per ICH guidelines. Linearity regression coefficients for both D and L-Proline are obtained as 0.999. Retrieval for D-Proline was obtained at 93 to 95% range for 4 levels. LoD and LoQ for both D- and L-Proline were detected as 0.6 and 2 ppm, respectively. Hence this method is newer, modest, particular and explicit chiral method.

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45

Zdunek-Zastocka, Edyta, Agnieszka Grabowska, Beata Michniewska y Sławomir Orzechowski. "Proline Concentration and Its Metabolism Are Regulated in a Leaf Age Dependent Manner But Not by Abscisic Acid in Pea Plants Exposed to Cadmium Stress". Cells 10, n.º 4 (20 de abril de 2021): 946. http://dx.doi.org/10.3390/cells10040946.

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The accumulation of proline is one of the defense mechanisms of plants against the harmful effects of adverse environmental conditions; however, when pea plants were treated for 12 h with CdCl2, the proline concentration decreased in the youngest A (not expanded) and B1 (expanded) leaves, and did not change significantly in the B2 (mature, expanded) or C (the oldest) leaves. After 24 h of cadmium (Cd) stress, the proline concentration remained low in A and B1 leaves, while in B2 and C leaves, it increased, and after 48 h, an increase in the proline concentration in the leaves at each stage of development was observed. The role of proline in the different phases of plant response to the Cd treatment is discussed. Changes in proline accumulation corresponded closely with changes in the transcript levels of PsP5CS2, a gene encoding D1-pyrroline-5-carboxylate synthetase involved in proline synthesis, and PsPDH1, a gene encoding proline dehydrogenase engaged in proline degradation. CdCl2 application induced the expression of PsProT1 and PsProT2, genes encoding proline transporters, especially during the first 12 h of treatment in A and B1 leaves. When the time courses of abscisic acid (ABA) and proline accumulation were compared, it was concluded that an increase in the proline concentration in the leaves of Cd-treated pea plants was more related to a decrease in chlorophyll concentration (leaves B2 and C) and an increase in the malondialdehyde level (A and B1 leaves) than with an increase in ABA concentration alone. Exogenous application of ABA (0.5, 5, 50 µM) significantly increased the proline concentration in the A leaves of pea plants only, and was accompanied by an elevated and repressed expression of PsP5CS2 and PsPDH1 in these leaves, respectively. The presented results suggest that under Cd stress, the accumulation of proline in leaves of pea plants may take place independently of the ABA signaling.

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46

L'Hostis, C., M. Geindre y J. Deshusses. "Active transport of l-proline in the protozoan parasite Trypanosoma brucei brucei". Biochemical Journal 291, n.º 1 (1 de abril de 1993): 297–301. http://dx.doi.org/10.1042/bj2910297.

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The characteristics of L-proline transport in the procyclic form of Trypanosoma brucei were studied by using L-[14C]proline and a quick separation technique by centrifugation through an oil mixture. L-Proline uptake displayed typical Michaelis-Menten kinetics, with a Km of 19 microM and a maximum transport velocity of 17 nmol/min per 10(8) cells at 27 degrees C. The maximum concentration gradient factor obtained after 1 min of incubation was 270-fold in 0.02 mM proline. Cells permeabilized with 80 microM digitonin were still able to accumulate 14C label, but to a lower extent. The temperature-dependence of proline uptake gave an apparent activation energy of 74.9 kJ.mol-1. In competition studies with a 10-fold excess of structural analogues, L-alanine, L-cysteine and L-azetidine-2-carboxylate were found to inhibit L-proline uptake. Variation of pH or addition of the protonophore carbonyl cyanide m-chlorophenylhydrazone (‘CCCP’) did not affect proline transport, showing that it is not driven by a protonmotive force. The absence of Na+, with or without monensin, did not affect proline transport. The absence of K+ and the addition of the Na+,K(+)-ATPase inhibitor ouabain had no significant effect on proline uptake activity. The thiol-modifying reagent iodoacetate (10 mM) decreased proline uptake by half. KCN (1 mM) inhibited proline uptake to a lesser extent, and the degree of inhibition was proportional to the intracellular ATP concentration. Preliminary experiments on proline transport in plasma-membrane vesicles of the cells, using a filtration technique, showed an uptake of proline (0.67 nmol/mg of protein) by the vesicles, but only in the presence of intravesicular ATP. The results thus obtained suggest that the proline carrier system in T. brucei is ATP-driven and independent of Na+, K+ or H+ co-transport.

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47

Guerrier, Gilles. "Effect of salt-stress on proline metabolism in calli of Lycopersicon esculentum, Lycopersicon pennellii, and their interspecific hybrid". Canadian Journal of Botany 73, n.º 12 (1 de diciembre de 1995): 1939–46. http://dx.doi.org/10.1139/b95-206.

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Amino acid pools and enzyme activities of NH3-assimilation (glutamine synthetase, glutamate synthase), proline biosynthesis (pyrroline-5-carboxylate reductase), proline catabolism (proline dehydrogenase, proline oxidase), and ornithine transamination (ornithine transaminase) were determined in control and salinized (140 mM NaCl) calli from tomato roots. Three populations were used: the domestic salt-sensitive Lycopersicon esculentum Mill. cv. P-73, the wild salt-tolerant Lycopersicon pennellii (Correll) D'Arcy, accession PE-47, and their F1 interspecific cross, for which the relative growth rate on salt media was intermediate to those of the parents. Compared with control conditions, proline levels increased with NaCl treatments by twofold, threefold, and sixfold in the wild species, the F1 hybrid, and the domestic species, respectively. This proline accumulation in the F1 and the domestic populations was not modulated by changes in the enzyme activities of proline biosynthesis or catabolism. NaCl tolerance, amino acid (proline, alanine, arginine, asparagine) content, and velocity of enzymes responsible for proline biosynthesis and catabolism are dependent on explant sources (cotyledon, root) from which the F1 calli were derived. The comparison of proline (PRO) responses in the different calli and populations indicated (i) various changes in anabolic or catabolic rates of PRO metabolism for a given range of PRO accumulation and (ii) the presence in the F1 of both wild and sensitive parent characters in growth and PRO responses. Key words: callus culture, Lycopersicon esculentum, Lycopersicon pennellii, F1 tomato, proline synthesis, proline catabolism, salt stress.

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Phang, James M., Jui Pandhare, Olga Zabirnyk y Yongmin Liu. "PPARγand Proline Oxidase in Cancer". PPAR Research 2008 (2008): 1–9. http://dx.doi.org/10.1155/2008/542694.

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Proline is metabolized by its own specialized enzymes with their own tissue and subcellular localizations and mechanisms of regulation. The central enzyme in this metabolic system is proline oxidase, a flavin adenine dinucleotide-containing enzyme which is tightly bound to mitochondrial inner membranes. The electrons from proline can be used to generate ATP or can directly reduce oxygen to form superoxide. Although proline may be derived from the diet and biosynthesized endogenously, an important source in the microenvironment is from degradation of extracellular matrix by matrix metalloproteinases. Previous studies showed that proline oxidase is a p53-induced gene and its overexpression can initiate proline-dependent apoptosis by both intrinsic and extrinsic pathways. Another important factor regulating proline oxidase is peroxisome proliferator activated receptor gamma (PPARγ). Importantly, in several cancer cells, proline oxidase may be an important mediator of the PPARγ-stimulated generation of ROS and induction of apoptosis. Knockdown of proline oxidase expression by antisense RNA markedly decreased these PPARγ-stimulated effects. These findings suggest an important role in the proposed antitumor effects of PPARγ. Moreover, it is possible that proline oxidase may contribute to the other metabolic effects of PPARγ.

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Guo, Shuaiqi, Xuxia Ma, Wenqi Cai, Yuan Wang, Xueqin Gao, Bingzhe Fu y Shuxia Li. "Exogenous Proline Improves Salt Tolerance of Alfalfa through Modulation of Antioxidant Capacity, Ion Homeostasis, and Proline Metabolism". Plants 11, n.º 21 (7 de noviembre de 2022): 2994. http://dx.doi.org/10.3390/plants11212994.

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Alfalfa (Medicago sativa L.) is an important forage crop, and its productivity is severely affected by salt stress. Although proline is a compatible osmolyte that plays an important role in regulating plant abiotic stress resistance, the basic mechanism of proline requires further clarification regarding the effect of proline in mitigating the harmful effects of salinity. Here, we investigate the protective effects and regulatory mechanisms of proline on salt tolerance of alfalfa. The results show that exogenous proline obviously promotes seed germination and seedling growth of salt-stressed alfalfa. Salt stress results in stunted plant growth, while proline application alleviates this phenomenon by increasing photosynthetic capacity and antioxidant enzyme activities and decreasing cell membrane damage and reactive oxygen species (ROS) accumulation. Plants with proline treatment maintain a better K+/Na+ ratio by reducing Na+ accumulation and increasing K+ content under salt stress. Additionally, proline induces the expression of genes related to antioxidant biosynthesis (Cu/Zn-SOD and APX) and ion homeostasis (SOS1, HKT1, and NHX1) under salt stress conditions. Proline metabolism is mainly regulated by ornithine-δ-aminotransferase (OAT) and proline dehydrogenase (ProDH) activities and their transcription levels, with the proline-treated plants displaying an increase in proline content under salt stress. In addition, OAT activity in the ornithine (Orn) pathway rather than Δ1-pyrroline-5-carboxylate synthetase (P5CS) activity in the glutamate (Glu) pathway is strongly increased under salt stress, made evident by the sharp increase in the expression level of the OAT gene compared to P5CS1 and P5CS2. Our study provides new insight into how exogenous proline improves salt tolerance in plants and that it might be used as a significant practical strategy for cultivating salt-tolerant alfalfa.

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Dillon, E. Lichar, Darrell A. Knabe y Guoyao Wu. "Lactate inhibits citrulline and arginine synthesis from proline in pig enterocytes". American Journal of Physiology-Gastrointestinal and Liver Physiology 276, n.º 5 (1 de mayo de 1999): G1079—G1086. http://dx.doi.org/10.1152/ajpgi.1999.276.5.g1079.

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Hypocitrullinemia and hypoargininemia but hyperprolinemia are associated with elevated plasma concentration of lactate in infants. Because the small intestine may be a major organ for initiating proline catabolism via proline oxidase in the body and is the major source of circulating citrulline and arginine in neonates, we hypothesized that lactate is an inhibitor of intestinal synthesis of citrulline and arginine from proline. To test this hypothesis, jejunum was obtained from 14-day-old suckling pigs for preparation of enterocyte mitochondria and metabolic studies. Mitochondria were used for measuring proline oxidase activity in the presence of 0–10 mMl-lactate. For metabolic studies, enterocytes were incubated at 37°C for 30 min in Krebs bicarbonate buffer (pH 7.4) containing 5 mMd-glucose, 2 mMl-glutamine, 2 mMl-[U-14C]proline, and 0, 1, 5, or 10 mM l-lactate. Kinetics analysis revealed noncompetitive inhibition of intestinal proline oxidase by lactate (decreased maximal velocity and unaltered Michaelis constant). Lactate had no effect on either activities of other enzymes for arginine synthesis from proline or proline uptake by enterocytes but decreased the synthesis of ornithine, citrulline, and arginine from proline in a concentration-dependent manner. These results demonstrate that lactate decreased intestinal synthesis of citrulline and arginine from proline via an inhibition of proline oxidase and provide a biochemical basis for explaining hyperprolinemia, hypocitrullinemia, and hypoargininemia in infants with hyperlactacidemia.

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