• Title/Summary/Keyword: Purine nucleoside phosphorylase

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Backbone NMR Assignments and Secondary Structure Determination of a Cupin-family Protein YaiE from Escherichia coli

  • Lee, Sung-Hee;Sim, Dae-Won;Kim, Eun-Hee;Kim, Ji-Hun;Won, Hyung-Sik
    • Journal of the Korean Magnetic Resonance Society
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    • v.21 no.2
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    • pp.50-54
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    • 2017
  • Cupin-superfamily proteins represent the most functionally diverse groups of proteins and include a huge number of functionally uncharacterized proteins. Recently, YaiE, a cupin protein from Escherichia coli has been suggested to be involved in a novel activity of pyrimidine/purine nucleoside phosphorylase (PPNP). In the present study, we achieved a complete backbone NMR assignments of YaiE, by a series of heteronuclear multidimensional NMR experiments on its [$^{13}C/^{15}N$]-enriched sample. Subsequently, secondary structure analysis using the assigned chemical shift values identified 10 obvious ${\beta}-strands$ and a tentative $3_{10}-helix$. Taken all together, the results constitute the first structural characterization of a putative PPNP cupin protein.

Purine Nucleoside Phosphorylase (PNP) Activity of Lymphocytes and T Cell Subsets in Peripheral Blood in Thyroid Tumors (갑상선 종양에 있어서 말초형 림프구의 Purine Nucleoside Phosphorylase (PNP) 활성과 T 세포 아형에 관한 연구)

  • Kim, Dong-Soo
    • The Korean Journal of Nuclear Medicine
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    • v.26 no.1
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    • pp.1-7
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    • 1992
  • To elucidate alteration of purine nucleoside phosphorylase (PNP) activity of peripheral lymphocytes and helper/inducer and suppressor/cytototxic T cells in patients with thyroid tumors, the author examined PNP activity, and $CD4^+\;and\;CD8^+$ cells of peripheral blood in 20 cases of simple goiter, 9 cases of thyroid adenoma and 20 cases of thyroid cancer as well as 11 cases of adult healthy subjects as control. Diagnoses were established on the basis of commonly accepted clinical and biochemical criteria in simple goiter and were confirmed histopathologically in thyroid adenoma and cancer. All blood was obtained from veins of the patients and control subjects in Pusan National University Hospital during the period of January to August, 1991. The results obtained were summarized as follows: 1) The PNP activity was significantly decreased or tended to be decreased in thyroid adenomas and cancers as compared with control subjects and simple goiters. 2) The percentage of CD8 cells was significantly decreased or tended to be decreased in thyroid cancers as compared with simple goiters, thyroid adenomas and control subjects. 3) The CD4/CD8 ratio was significantly increased or tended to be increased in thyroid cancer as compared with simple goiters, thyroid adenomas and control subjects. On the basis of the results, it can be suggested that the immunodysfunction in thyroid cancer may be due to decreased suppressor/cytotoxic T cells, and the estimation of PNP activity of peripheral lymphocyte is a helpful test in detecting the immune status in thyroid tumors.

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Effect of S-Adenosylmethionine on Hepatic Injury from Sequential Cold and Warm Ischemia

  • Lee, Yu-Bum;Lee, Sun-Mee
    • Archives of Pharmacal Research
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    • v.23 no.5
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    • pp.495-500
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    • 2000
  • We investigated whether S-adenosylmethionine (SAM) treatment improved ischemic injury using perfused rat liver after sequential periods of 24 h cold and 20 min re-warming ischemia. SAM (100 $\mu\textrm{mol/L}$) was added to University of Wisconsin (UW) solution and Ringers lactate solution. After cold and sequential warm ischemia, releases of lactate dehydrogenase (LDH) and purine nucleoside phosphorylase (PNP) markedly increased during repefusion. The increase in PNP was significantly reduced by SAM treatment. While the concentration of reduced glutathione (GSH) in ischemic livers significantly decreased, the concentration of glutathione disulfide (GSSG) increased. This decrease in GSH and increase in GSSG were suppressed by SAM treatment. Lipid peroxidation was elevated in cold and warm ischemic and reperfused livers, but this elevation was also prevented by SAM treatment. Hepatic ATP levels were decreased in the ischemic and reperfused livers to 42% of the control levels. However, treatment with SAM resulted in significantly higher ATP levels and preserved the concentration of AMP in ischemic livers. Our findings suggest that SAM prevents oxidative stress and lipid peroxidation and helps preserve hepatic energy metabolism.

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Ischemic Preconditioning Ameliorates Hepatic Injury from Cold Ischemia/Reperfusion

  • PARK Sang-Won;LEE Sun-Mee
    • Biomolecules & Therapeutics
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    • v.13 no.3
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    • pp.127-132
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    • 2005
  • We investigated whether ischemic preconditioning (IPC) protects liver against cold ischemic injury using isolated perfused rat liver. Rat livers were preconditioned by 5 minutes of ischemia and 5 minutes of reperfusion and preserved for 30 hours at $4^{\circ}C$ in University of Wisconsin solution. Livers were then reperfused for 120 minutes. Oxygen uptake and bile flow in ischemic livers markedly decreased during reperfusion. These decreases were prevented by IPC. Portal pressure was elevated in cold ischemic and reperfused livers and this elevation was prevented by IPC. Lactate dehydrogenase and purine nucleoside phosphorylase activities markedly increased during reperfusion. These increases were prevented by IPC. The ratio of reduced glutathione to glutathione disulfide was lower in ischemic livers. This decrease was prevented by IPe. Our findings suggest that IPC protects the liver against the deleterious effect of cold ischemia/reperfusion, and this protection is associated with the reduced oxidative stress.

Role of Kupffer Cells in Cold/warm Ischemia-Reperfusion Injury or Rat Liver

  • Lee, Young-Goo;Lee, Sang-Ho;Lee, Sun-Mee
    • Archives of Pharmacal Research
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    • v.23 no.6
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    • pp.620-625
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    • 2000
  • The mechanisms of liver injury from cold storage and reperfusion are not completely under-stood. The aim of the present study was to investigate whether the inactivation of Kupffer cells (KCs) by gadolinium chloride ($GdCl_3$) modulates ischemia-reperfusion injury in the rat liver. Hepatic function was assessed using an isolated perfused rat liver model. In livers subjected to cold storage at $4^{\circ}C$ in University of Wisconsin solution for 24 hrs and to 20 min rewarm-ing ischemia, oxygen uptake was markedly decreased, Kupffer cell phagocytosis was stimulated, releases of purine nucleoside phosphorylase and lactate dehydrogenase were increased as compared with control livers. Pretreatment of rats with $GdCl_3$) , a selective KC toxicant, suppressed kupffer cell activity, and reduced the grade of hepatic injury induced by ischemia-reperfusion. While the initial mixed function oxidation of 7-ethoxycoumarin was not different from that found in the control livers, the subsequent conjugation of its meta-bolite to sulfate and glucuronide esters was suppressed by ischemia-reperfusion, CdCl$_3$restored sulfation and glucuronidation capacities to the level of the control liver. Our findings suggest that Kupffer cells could play an important role in cold/warm ischemia-reperfusion hepatic injury.

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Antiinflammatory, Analgesic and Antihyperuricemic Effects of 'Gyejakjimo-Tang' in Rats (계작지모탕(桂芍知母湯)의 소염.진통작용 및 Alcohol성 고뇨산혈증(高尿酸血症)에 미치는 영향)

  • Kim, Soon-Shin;Kim, Hye-Kyung;Choi, Jong-Won;Lee, Chung-Kyu
    • Korean Journal of Pharmacognosy
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    • v.26 no.1
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    • pp.66-73
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    • 1995
  • 'Gyejakjimo-Tang(桂芍知母湯)', which is composed of Cinnamon bark(桂枝), Peony root(芍藥), Anemarrhena root(知母) and other seven herbs, is described as antipyretic, diuretic and analgesic prescription in traditional medical literatures including Geumgwe-Yoryak(金櫃要略). So it is being used in the treatment of gout clinically in oriental region. As the results of the pharmacological and biochemical trials of the prescription, it was found to have antiinflammatory and significant analgesic effects indicated by carrageenin edema, dye permeabilities and writhing behavior. And it potentiated the output of uric acid in blood and the increase of uric acid in urine of alcohol-toxicated rats, which mean the decrease of uric acid level only by excretion procedure. But the prescription didn't show any effects on the activities of adenine/guanine deaminase, purine nucleoside phosphorylase, xanthine oxidase or uricase, which are related with formation and metabolism of uric acid.

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