• Bulletin of the Korean Chemical Society
• /
• 제31권7호
• /
• pp.2061-2064
• /
• 2010

• 통합자연과학논문집
• /
• 제8권2호
• /
• pp.99-106
• /
• 2015

Novel 2'(${\beta}$)-fluoro-3'(${\alpha}$)-hydroxy-threose nucleosides (iso-FMAU) as antiviral agents were designed and racemically synthesized from Solketal. Condensation successfully proceeded from a glycosyl donor 9 under $Vorbr{\ddot{u}}ggen$ conditions yielded the nucleoside analogues. Ammonolysis and hydrolysis of isopropylidene protection group gave the desired nucleoside analogues 12, 15, 18, and 19. The antiviral activities of the synthesized compounds were evaluated against the HIV-1, HSV-1, HSV-2 and HCMV. Compound 12 displayed some anti-HCMV activity ($EC_{50}=24.7{\mu}g/ml$) without exhibiting any cytotoxicity up to $100{\mu}M$.

• 미생물학회지
• /
• 제32권3호
• /
• pp.222-231
• /
• 1994

Saccharomyces cerevisiae에서 얻은 purine nucleoside phosphorylase (PNP)의 반응 기작을 밝히기 위해 반응속도론적 분석이 수행되어졌다. 반응기작에 PNP${\cdot}$phosphate와 PNP${\cdot}$ribose 1-phosphate의 binary complex가 형성되는 것으로 추정되어진다. Initial velocity와 product inhibition study의 결과는 반응이 ordered bi, bi reaction으로 일어난다는 것과 일치하고 있다. 두 개의 기질중 무기인산이 효소에 먼저 붙고, 그 다음에 nucleoside, 그리고 base가 효소를 떠나는 첫 번째 생성물이고 마지막으로 ribose 1-phosphate가 생성되고 효소는 원래의 상태로 돌아간다. 반응속도론적 분석에 이해 제안된 작용기작은 sulfhydryl reagents인 p-chloromercuribenzoate(PCMB) and 5,5'-dithiobisnitrobenzoate (DTNB)에 의한 효소의 불활성화에 대한 기질으 보호작용의 결과와 일치하고 있다. PNP는 ribose 1-phosphate와 phosphate에 의해 보호되지만 nucleoside나 base에 의해서는 아무런 효과과 없다는 사실은 반응 순서가 효소에 무기인산이 먼저 붙는 ordered bi, bi 기작이라는 것을 지지하고 있다. PCMB 나 DTNB에 의해 불활성화된 PNP는 dithiothreitol(DTT)에 의해서는 활성이 완전히 회복되고 2-mercaptoethanol에 의해서는 77%의 활성이 회복된다는 사실은 효소의 불활성화가 가역적이라는 것을 시사하고 있다. PCMB에 의해 불활성화된 효소는 inosine이 변화하는 기질일때 정상효소보다 높은 $K_m$과 낮은 $V_m$ 값을 보여주고 이런 현상은 DTT 처리시 원래의 상태로 돌아온다. DTNB에 의해 불활성화된 효소는 PCMB 처리시와 비슷하게 정상효소보다 높은 $V_m$ 값을 보이지만 $V_m$ 값은 큰 변화가 없다. S. cerevisiae PNP에서 발견되는 높은 무기인산의 농도에서의 하위단위체간의 음성적 협동성이 PCMB나 DTNB를 처리한 PNP에서는 보이지 않았다.

• BMB Reports
• /
• 제35권4호
• /
• pp.403-408
• /
• 2002

A hypothetical 21.0 kDa protein (ORF O197) from Escherichia coli K-12 was cloned, purified, and characterized. The protein sequence of ORF O197(termed EcO197) shares a 33.5% identity with that of a novel NTPase from Methanococcus jannaschii. The EcO197 protein was purified using Ni-NTA affinity chromatography, protease digestion, and gel filtration column. It hydrolyzed nucleoside triphosphates with an O6 atom-containing purine base to nucleoside monophosphate and pyrophosphate. The EcO197 protein had a strong preference for deoxyinosine triphosphate (dITP) and xanthosine triphosphate (XTP), while it had little activity in the standard nucleoside triphosphates (dATP, dCTP, dGTP, and dTTP). These aberrant nucleotides can be produced by oxidative deamination from purine nucleotides in cells; they are potentially mutagenic. The mutation protection mechanisms are caused by the incorporation into DNA of unwelcome nucleotides that are formed spontaneously. The EcO197 protein may function to eliminate specifically damaged purine nucleotide that contains the 6-keto group. This protein appears to be the first eubacterial dITP-and XTP-hydrolyzing enzyme that has been identified.

• Biomolecules & Therapeutics
• /
• 제13권3호
• /
• pp.127-132
• /
• 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.

• 생약학회지
• /
• 제16권3호
• /
• pp.129-135
• /
• 1985

In order to search for potential antidotes for T-2 toxin poisoning, seven Chinese herbal drug extracts and five natural constituents were tested on mice intoxicated with T-2 toxin. When extracts of Panax ginseng and Atractylodes japonica (500 mg/kg) were administered p.o. once 3 hrs before and once 1 hr after T-2 toxin treatment, a 30% complete survival rate was noted. In case of Paeonia albiflora var. typica, a 30% complete survival rate was also produced at a dose of 250 mg/kg. Other extracts, Glycyrrhiza uralensis, Scutellaria baicalensis, Rehmannia glutinosa and Plantago asiatica exhibited no significant protection from the T-2 toxin poisoning. A nucleoside, thymidine showed protective activity against T-2 toxin toxicity and it produced a 40% complete survival rate when administered i.p. once 0.5 hr after T-2 toxin treatment. Other natural constituents, aucubin, vitamin C and E, and lipoic acid did not show any significant protective activities.

• Journal of Preventive Veterinary Medicine
• /
• 제42권4호
• /
• pp.157-162
• /
• 2018

This study evaluated the protective effects of a combination of eight B. abortus recombinant proteins that were cloned and expressed into a pMal vector system and $DH5{\alpha}$: nucleoside diphosphate kinase (rNdk), 50S ribosomal protein (rL7/L12), malate dehydrogenase (rMDH), DNA starvation/stationary phase protection protein (rDps), elongation factor (rTsf), arginase (rRocF), superoxide dismutase (rSodC), and riboflavin synthase subunit beta (rRibH). The proteins were induced, purified, and administered intraperitoneally into BALB/c mice. The mice were immunized three times at weeks 0, 2, and 5 and then infected intraperitoneally (IP) with $5{\times}10^4CFU$ of virulent B. abortus 544 one week after the last immunization. The spleens were collected and the bacterial burden was evaluated at four weeks post-infection. The results showed that this combination produced a significant reduction of the bacterial burden in the spleen with a log reduction of 1.01 compared to the PBS group. Cytokine analysis revealed induction of the cell-mediated immune response in that TNF (tumor necrosis factor) and proinflammatory cytokines IL-6 (Interleukin 6) and MCP-1 (macrophage chemoattractant protein-1) were elevated significantly. In summary, vaccination with a combination of eight different proteins induced a significant protective effect indicative of a cell mediated immune response.

• Journal of Microbiology and Biotechnology
• /
• 제29권2호
• /
• pp.330-338
• /
• 2019

Chronic infection with intracellular Brucella abortus (B. abortus) in livestock remains as a major problem worldwide. Thus, the search for an ideal vaccine is still ongoing. In this study, we evaluated the protective efficacy of a combination of B. abortus recombinant proteins; superoxide dismutase (rSodC), riboflavin synthase subunit beta (rRibH), nucleoside diphosphate kinase (rNdk), 50S ribosomal protein (rL7/L12) and malate dehydrogenase (rMDH), cloned and expressed into a pMal vector system and $DH5{\alpha}$, respectively, and further purified and applied intraperitoneally into BALB/c mice. After first immunization and two boosters, mice were infected intraperitoneally (IP) with $5{\times}10^4CFU$ of virulent B. abortus 544. Spleens were harvested and bacterial loads were evaluated at two weeks post-infection. Results revealed that this combination showed significant reduction in bacterial colonization in the spleen with a log protection unit of 1.31, which is comparable to the average protection conferred by the widely used live attenuated vaccine RB51. Cytokine analysis exhibited enhancement of cell-mediated immune response as IFN-${\gamma}$ is significantly elevated while IL-10, which is considered beneficial to the pathogen's survival, was reduced compared to control group. Furthermore, both titers of IgG1 and IgG2a were significantly elevated at three and four-week time points from first immunization. In summary, our in vivo data revealed that vaccination with a combination of five different proteins conferred a heightened host response to Brucella infection through cell-mediated immunity which is desirable in the control of intracellular pathogens. Thus, this combination might be considered for further improvement as a potential candidate vaccine against Brucella infection.

• Journal of Chest Surgery
• /
• 제33권2호
• /
• pp.117-124
• /
• 2000

Background: Nucleoside transport inhibitor(NTI) Keeps AMP, ADP, ATP levels high in myocytes by inhibiting adenosine cataboilsm so that it may preserve the myocardial contractability during ischemia In this study we investigated the effects of cyclic AMP phosphodiesterase inhibor(C-AMP PDSI) and S-P-nitrobenzyl-6 -thioniosine(NBT; a sort of NIT) on myocadial preservation and changes of constituent enzyme. Material and method: Twenty-six isolated rabbit hearts were perfused with Krebs-Henseleit buffer solution for 20 minutes arrested for 20 minutes and ten reperfused for 30 minutes. The following four groups were prepared and hemodynamic changes coronary effluent lactate dehydrogenase (LDH) a-hydroxybutylic accid(a-HBD) levels and myocardial LDH creatine kinase-MB (CK-MB) adenosine deaminase(ADA) a-HBD levels and myocardial LDH creatine kinase-MB (CK-MB) adenosine deaminase(ADA) a-HBD levels were analysed before and after cardiac arest ; Group I(control) ; the heart was only perfused with K-H ; Group II ; the heart was perfused with K-H including C-AMP PDSI(Amrinone 25mg/L); Group III ; the heart was perfused with K-H including NBT(4.19mg/L) ; Group IV ; the heart was perfused with K-H including C-AMP PDSI + NBT. Result : Left venticular developed pressure(LVDP) at 10 minutes of the equilibrium was significantly higher in group III(72.1$\pm$5.3 mmHg p<0.01) and group III(72$\pm$5.6 mmHg P<0.025) as compared with group I (40.8$\pm$4.7mmHg) and LVDP at 20 minutes of the reperfusion was significantly higher in group II(74$\pm$5.3mmHg p<0.01) and group III(72$\pm$5.6mmHg p<0.025) as compared with group I (44.2$\pm$4.6mmHg). Percentage recovery of LVDP at the reperfusion was the highest in group II(123.3%) Percentage recovery of coronary flow at the equilibrium reperfusion were higher in group II(310%, 270%) group III(230%, 290%) group IV(310%, 280%) as compared with group I (100%) respectively. Myocadial LDH level was significant lower in group IV(33495$\pm$1802 IU/gm p<0.04) as compared with group I(48767$\pm$1421 IU/gm) Myocadial CK-MB level was significant higher in group II(74820$\pm$1421 IU/gm) compared with group I (45450$\pm$1737 IU/gm) Myocadial ADA level was significant higher group IV(1215$\pm$8 IU/gm p<0.05) compared with group I(125$\pm$15 IU/gm) but there was no significant difference between group I and group II ,III, IV in changes of coronary effluent LDH, a-HBD levels. Conclusion: C-AMP PDSI solely appears to have a better effect on myocardial preservation after ischemia than NBT but with no synergistic effect and it could keep CK-MB leve high in myocardial tissues.

• 생명과학회지
• /
• 제33권9호
• /
• pp.746-753
• /
• 2023

바이러스성 전염병은 전 세계 공중 보건에 가장 큰 위협 중 하나로 간주된다. 최근 중증급성호흡기증후군 코로나바이러스-2(SARS-CoV-2)로 인한 COVID-19 대유행은 신종 바이러스 감염의 위협을 극명하게 상기시켜 주었다. 효율적인 백신과 치료제 개발 및 생산은 팬데믹을 퇴치할 수 있는 유일한 대안일 것이며 COVID-19 대유행은 새로운 바이러스성 질병을 통제하고 예방하기 위한 새로운 백신 플랫폼의 필요성을 보여주었다. 기존의 백신 플랫폼인 약독화 생백신, 불활성화 백신은 백신 개발 속도, 제조 등이 광범위한 백신 적용을 위한 긴급 사용에 한계가 있다. 흥미롭게도, COVID-19 예방을 위한 SARS-CoV-2 mRNA-지질나노입자(LNP) 플랫폼은 기존 백신 플랫폼 한계에 대한 효과적인 대안임이 확인되었다. 또한 COVID-19 mRNA 핵산 백신과 나노입자 기반 플랫폼은 SARS-CoV-2 및 변종 SARS-CoV-2 모두에 효과적인 백신임이 확인되었다. 이 논문에서는 mRNA 백신, 디지털 백신 및 나노입자백신 등의 차세대 백신 플랫폼을 중점으로 백신 기술 및 플랫폼의 장단점에 대해 기술하였다.