• 제목/요약/키워드: $C_4-pathway$

검색결과 914건 처리시간 0.03초

L-Ascorbic Acid의 생체분해 (A Possible Enzymatic Catabolism of L-Ascorbic Acid via $\alpha$-Ketoaldehydes)

  • 강사욱
    • 미생물학회지
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    • 제23권4호
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    • pp.302-308
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    • 1985
  • L-Ascorbic aciddm ltodcp 산화분해과정중 ${\alpha}$-ketoaldehyde의 한 종류인 3,4,5-trihydroxy-2-keto-L-valeral-dehyde(L-xylosone)가 형성된다는 사실을 핵자기공명스펙트럼분석법으로 확인하였다. 이 물질은 glyoxalase system에 의해 L-xylonic acid로 변환되고 계속해서 L-erythroascorbic acid로 산화된다. 이러한 근거 위에서 vitamin C의 분해과정이 vitamic C 이외의 두종류의 ${\gamma}$-lactones-과 3종류의 ${\alpha}$-ketoaldehydes로 구성된 분해경로를 갖는다는 사실을 제안하였다.

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Jurkat T 면역세포에서 Phosphoinositides의 가수분해를 증가시키는 약용식물 추출물의 검색 (Screening of the Extracts of Herbal Medicines which Stimulate the Hydrolysis of Phosphoinositides in Jurkat T-lymphocyte Cells)

  • 민도식;이영한;백석환;서판길;류성호
    • Biomolecules & Therapeutics
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    • 제4권2호
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    • pp.148-153
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    • 1996
  • Activation of the T lymphocytes results in a variety of early biochemical events ultimately leading to cell proliferation and lymphokine production. Stimulation of the signal transduction cascade in T cells through the T cell receptor coincides with activation of the phosphatidylinositol-phospholipase C (PI-PLC) pathway. Therefore, we have established a model system to screen immune-simulator that can increase the hydrolysis of phosphoinositides in human T cell leukemia Jurkat cells. As a result of screening from herbal medicine extract, 4 extracts (O1ibanum, Ephedrae Herba, Real Gar, Saussureae Radix) were found 14 increase the production of inositol phosphates. All the active fraction from the four kinds of extract were fluted in a different retention time on C-18 HPLC and these active fraction also showed difference in cell specificity. And all the active fractions increased DNA synthesis in T cell. Therefore, it is suggested that the active fraction among 4 extracts might contain a compound having different properties one another.

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고추에서 분리한 Cinnamate 4-Hydroxylase 유전자의 분자생물학적 특성 (Molecular Characterization of Cinnamate 4-Hydroxylase gene in Red Hot Pepper (Capsicum annuum L.))

  • 김계원;하선화;조강진;김은주;이민경;유재주;김종국;이신우
    • Journal of Plant Biotechnology
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    • 제32권3호
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    • pp.167-173
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    • 2005
  • 본 연구는 고추열매의 capsaicinoid 생합성 조절 기작을 연구하고자 general phenylpropanoid pathway의 2번째 단계에 작용하는 것으로 알려진 3종류의 c4h cDNA clone을 확보하여 염기서열을 분석한 결과, pc4h1와 pc4h2의 크기는 각각 1,775 bp와 1,655 bp으로 505개의 아미노산으로 구성된 펩티드를 암호하는 full length의 ORF를 갖추고 있었으나 pc4h3는 5'-말단의 coding 영역 일부가 소실 되었다. 이들은 공히 모든 cytochrome P450 효소에서 진화학적으로 보존되어 있는 3종류의 conserved region 즉 domain 1(proline-rich region), domain 2 (threonine-containing binding pocket for the oxygen molecule), 그리고domain 3(heme binding region)을 포함하고 있었으며 evolutionary tree분석을 통하여 pc4h1와 pc4h2는 모두 Class I에 속하는 것으로 서로 간에는 95.8%의 유사성을 나타내어 거의 동일한 유전자인 것으로 조사되었다. 특히 Class II로 분류된 Citrus sinensis C4H1과 Phaseolus vulgaris C4H와는 단지 64.9에서 64.5%의 homology를 나타내었다. 또한 pc4h2는 상처를 주지 않은 조직에서는 비교적 적은 양의 mRNA 발현수준을 보였으나 상처를 가한 후 6시간의 열매에서는 400%, 뿌리에서는 200%까지 그 발현 양이 증가하였다. 이와 유사하게 pc4h1의 전사량도 상처에 의하여 유도는 되나 basal level이 pc4h2보다 높아서 발현증가 비율은 그다지 높지 않았다. 반면에 pc4h3 유전자는 상처를 주지 않은 모든 조직에서 거의 발현되지 않았으며 상처에 의하여서도 전혀 반응을 하지 않았다.

Hepa1c1c7 세포에서 카드뮴에 의한 세포사멸 신호전달체계에 관한 연구 (Apoptotic Signaling Pathway by Cadmium in Hepalclc7 cells)

  • 오경재;염정호
    • Toxicological Research
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    • 제17권3호
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    • pp.215-223
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    • 2001
  • 카드뮴의 주요한 표적장기이며 카드뮴이 만성 및 급성 폭로시 축적되는 가장 중요한 장기인 간의 세포독성을 Hepalclc7세포에서 caspases및 Bax단백질의 활성과 발현 그리고 미토콘드리아 세포막 전위 변화(MPT) 등을 조사하여 다음과 같은 결과를 얻었다. 1. 카드뮴은 농도의존적으로 간세포인 Hepalclc7 세포의 생존율을 감소시켰다. 2. 카드뮴을 농도별로 처리하였을 때 100 M 이상의 농도에서 세포사멸의 특징중의 하나인 DNA분절현상을 확인하였다. 3. 카드뮴 처리 후 caspase-3, caspase-8, caspase-9 의 활성변화를 조사한 결과 caspase-3,-9 pretease 활성이 시간이 경과함에 따라 증가하였다. 4. 카드뮴 처리 후 cytochrome c가 세포질내로 방출되었고 이는 caspase-9 proteas의 활성화를 유도하였다. 5. 카드뮴 처리 후 Bax가 세포질에서 미토콘드리아로 이동하여 cytochrome c의 세포질내로의 방출에 관여하였다. 6. 카드뮴 처리시 미토콘드리아 세포막 전위차의 감소를 JC-1 형광염색을 통하여 확인하였다. 이상의 결과는 카드뮴에 의한 Hepalclc7 세포사멸의 신호전달기전은 세포질내에 있는 Bax가 미토콘드리아로 이동, cytochrome c의 세포질내로의 방출, 그리고 caspase-3, 9 pretease 활성화를 의해서 매개되는 것으로 판단된다. 또한 Bax 단백질의 발현변화가 미토콘드리아의 기능변화에 기여하였으리라 사료된다.

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B-splint법에 의한 순간 회전 중심로 결정과 하악운동에 관한 연구 (A study on the determination of the instantaneous center of rotation pathway and the movement of the mandible by using the B-spline method)

  • 강동완;계기성
    • 대한치과보철학회지
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    • 제27권1호
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    • pp.55-81
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    • 1989
  • Recently the instantaneous center concept has been to understand the biomechanics by which a tissue derangement causes a mechanical derangement in human joint. Therefore, to understand the biomechanics of temporomandibular joint (T.M.J.) as a part of human joint, it is necessary to clarify the instantaneous center of rotation (I.C.R.) in the mandibular movement. Twenty male subjects without T.M.J. disorder and mandibular deviation during the mandibular movement were selected for this study. The habitual opening and closing paths were recorded on the paper of the sagittal metal plate by two pencil markers connected to the resin open clutch attached on the lower teeth, which was designed for this study. The coordinates of the 33-target points and the 109-anatomical landmarks were obtained using a Summagraphic digitizer connected to a 18AT computer. The original raw data of the opening and closing paths were smoothed by B-spline curve fitting technique and then the I.C.R. pathways were determined mathematically by the computer using algorithm for finding the I.C.R. of a planer rigid body model. Also the opening and closing movements of the mandible were simulated according to the determined I.C.R. The results obtained from this study were as follows. 1. At the early opening and the last closing, I.C.R's were almost distributed around the mastoid process outside the mandibular body without the presence in the region of the mandibular condyle. 2. The I.C.R. pathway showed variable patterns to each subject at the opening and closing movements. 3. The K constant with uniform pattern was obtained by the rotation angle times the radius, which was assumed to the index of the mandibular movement. 4. The opening and closing movements of the mandible were simulated by the I.C.R. pathways at the habitual opening and closing movements. 5. The mandibular condyle was rotated or translated accordng to the relative rotation angle and radius of the determinant factors of K contant.

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병풀(Centella asiatica) 및 아시아티코사이드는 미토콘드리아 호흡 및 TLR4 경로를 통해 H2O2 유도 세포염증 조절 (Centella asiatica and Asiaticoside Regulate H2O2-induced Cellular Inflammation via Mitochondrial Respiration and the TLR4 Pathway)

  • 지주리;남영선;강상모
    • 생명과학회지
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    • 제31권4호
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    • pp.389-399
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    • 2021
  • 이 연구는 인간진피섬유아(HDF)세포에서 병풀 및 아시아티코사이드가 H2O2 유래 세포주기 정지기, 미토콘드리아 활성 및 염증성 사이토카인에 미치는 영향을 조사하였다. 병풀 80% 메탄올 추출물, 에틸아세티이트 분획물 및 병풀의 대표물질인 아시아티코사이드를 사용하였다. 병풀 추추물, 에틸아세테이트 분획 및 아시아티코사이드로 처리한 세포는 낮은 수준의 TNF-α 및 IL-6을 분비하였고, 아시아티코사이드의 항산화 효과는 병풀 추출물 및 에틸아세테이트 분획물보다 높았다. 아시아티코사이드 처리는 미토콘드리아의 막포텐셜을 증가시키고, 미토콘드리아를 정상으로 되돌렸다. 스트레스 유도 후 에틸아세테이트 분획물 및 아시아티코사이드에 의해 미토콘드리아 산소 소비율이 증가하였고, TLR4-MyD88-TRAF6-p65 경로가 재감소하였다. 이러한 결과는 병풀 추출물, 에틸 아세테이트 분획 및 아시아티코사이드가 HDF 세포의 미토콘드리아 활성을 조절할 뿐 아니라 항산화 및 항염증에 효과 있음을 시사한다.

벼와 고추에서 UV와 상처가 PAL 및 C4H 효소 활성에 미치는 영향 (Phenylalanine Ammonia Lyase and Cinnamic Acid 4-Hydroxylase Activities of Rice and Pepper in response to UV and Wounding)

  • Kim, Mi-Young;Yoon, Yong-Hwi;Lee, Jung-Hoon;Kim, Hak-Yoon;Shin, Dong-Hyun;Lee, In-Jung;Kim, Dal-Ung;Kim, Kil-Ung
    • 생명과학회지
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    • 제12권3호
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    • pp.274-280
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    • 2002
  • Phenylpropanoid pathway 생성물질은 식물의 self-defense에 관계하며 이러한 물질들은 UV뿐 아니라 wounding, pathogen과 같은 environmental stress에 의해 생성되는 것으로 알려져 있다. 벼에서 PAL mRNA 는 UV 조사 후 12시간에서 48시간까지는 증가하였으나 48시간부터 60시간까지는 점점 줄어드는 경향을 보였다. 한편 PAL의 활성은 UV조사 후 24시간에서 가장 높았지만 상처에 의해서는 PAL의 활성이 벼에서는 증가하지 않았다. 그러나 고추에서는 UV조사와 상처를 준 후 24시간과 10시간에서 각각 높은 활성을 나타내었다. 벼와 고추 모두 cinnamic acid 4-hydroxylase의 활성은 상처를 준 후 12시간에서 증가하였지만 UV 조사는 C4H 활성에 영향을 주지 않았다. 이러한 결과로 볼 때 벼와 고추에서는 UV 조사와 상처가 모두 PAL, C4H 효소활성에 영향을 주는 것으로 나타났다.

Ginsenoside Re inhibits pacemaker potentials via adenosine triphosphate-sensitive potassium channels and the cyclic guanosine monophosphate/nitric oxide-dependent pathway in cultured interstitial cells of Cajal from mouse small intestine

  • Hong, Noo Ri;Park, Hyun Soo;Ahn, Tae Seok;Kim, Hyun Jung;Ha, Ki-Tae;Kim, Byung Joo
    • Journal of Ginseng Research
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    • 제39권4호
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    • pp.314-321
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    • 2015
  • Background: Ginseng belongs to the genus Panax. Its main active ingredients are the ginsenosides. Interstitial cells of Cajal (ICCs) are the pacemaker cells of the gastrointestinal (GI) tract. To understand the effects of ginsenoside Re (GRe) on GI motility, the authors investigated its effects on the pacemaker activity of ICCs of the murine small intestine. Methods: Interstitial cells of Cajal were dissociated from mouse small intestines by enzymatic digestion. The whole-cell patch clamp configuration was used to record pacemaker potentials in cultured ICCs. Changes in cyclic guanosine monophosphate (cGMP) content induced by GRe were investigated. Results: Ginsenoside Re ($20-40{\mu}M$) decreased the amplitude and frequency of ICC pacemaker activity in a concentration-dependent manner. This action was blocked by guanosine 50-[${\beta}-thio$]diphosphate [a guanosine-5'-triphosphate (GTP)-binding protein inhibitor] and by glibenclamide [an adenosine triphosphate (ATP)-sensitive $K^{+}$ channel blocker]. To study the GRe-induced signaling pathway in ICCs, the effects of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (a guanylate cyclase inhibitor) and RP-8-CPT-cGMPS (a protein kinase G inhibitor) were examined. Both inhibitors blocked the inhibitory effect of GRe on ICC pacemaker activity. L-NG-nitroarginine methyl ester ($100{\mu}M$), which is a nonselective nitric oxide synthase (NOS) inhibitor, blocked the effects of GRe on ICC pacemaker activity and GRe-stimulated cGMP production in ICCs. Conclusion: In cultured murine ICCs, GRe inhibits the pacemaker activity of ICCs via the ATP-sensitive potassium ($K^{+}$) channel and the cGMP/NO-dependent pathway. Ginsenoside Re may be a basis for developing novel spasmolytic agents to prevent or alleviate GI motility dysfunction.

Vasoactive Intestinal Polypeptide Inhibits Pacemaker Activity via the Nitric Oxide-cGMP-Protein Kinase G Pathway in the Interstitial Cells of Cajal of the Murine Small Intestine

  • Kim, Byung Joo;Lee, Jae Hwa;Jun, Jae Yeoul;Chang, In Youb;So, Insuk;Kim, Ki Whan
    • Molecules and Cells
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    • 제21권3호
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    • pp.337-342
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    • 2006
  • Interstitial cells of Cajal (ICCs) are pacemaker cells that activate the periodic spontaneous depolarization (pacemaker potentials) responsible for the production of slow waves in gastrointestinal smooth muscle. The effects of vasoactive intestinal polypeptide (VIP) on the pacemaker potentials in cultured ICCs from murine small intestine were investigated by whole-cell patch-clamp techniques. Addition of VIP (50 nM-$1{\mu}M$) decreased the amplitude of pacemaker potentials and depolarized resting membrane potentials. To examine the type of receptors involved in ICC, we examined the effects of the $VIP_1$ agonist and found that it had no effect on pacemaker potentials. Pretreatment with $VIP_1$ antagonist ($1{\mu}M$) for 10 min also did not block the VIP (50 nM)-induced effects. On the other hand exposure to 1H-(1,2,4)oxadiazolo(4,3-A)quinoxalin-1-one (ODQ, $100{\mu}M$), an inhibitor of guanylate cyclase, prevented VIP inhibition of pacemaker potentials. Similarly KT-5823 ($1{\mu}M$) or RP-8-CPT-cGMPS ($10{\mu}M$), inhibitors of protein kinase G (PKG) blocked the effect of VIP (50 nM) on pacemaker potentials as did N-nitro-L-arginine (L-NA, $100{\mu}M$), a non-selective nitric oxide synthase (NOS) inhibitor. These results imply that the inhibition of pacemaker activity by VIP depends on the NO-cGMP-PKG pathway.

Anti-thrombotic effects of ginsenoside Rk3 by regulating cAMP and PI3K/MAPK pathway on human platelets

  • Hyuk-Woo Kwon ;Jung-Hae Shin ;Man Hee Rhee ;Chang-Eun Park ;Dong-Ha Lee
    • Journal of Ginseng Research
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    • 제47권6호
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    • pp.706-713
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    • 2023
  • Background and objective: The ability to inhibit aggregation has been demonstrated with synthetically derived ginsenoside compounds G-Rp (1, 3, and 4) and ginsenosides naturally found in Panax ginseng 20(S)-Rg3, Rg6, F4, and Ro. Among these compounds, Rk3 (G-Rk3) from Panax ginseng needs to be further explored in order to reveal the mechanisms of action during inhibition. Methodology: Our study focused to investigate the action of G-Rk3 on agonist-stimulated human platelet aggregation, inhibition of platelet signaling molecules such as fibrinogen binding with integrin αIIbβ3 using flow cytometry, intracellular calcium mobilization, dense granule secretion, and thromboxane B2 secretion. In addition, we checked the regulation of phosphorylation on PI3K/MAPK pathway, and thrombin-induced clot retraction was also observed in platelets rich plasma. Key Results: G-Rk3 significantly increased amounts of cyclic adenosine monophosphate (cAMP) and led to significant phosphorylation of cAMP-dependent kinase substrates vasodilator-stimulated phosphoprotein (VASP) and inositol 1,4,5-trisphosphate receptor (IP3R). In the presence of G-Rk3, dense tubular system Ca2+ was inhibited, and platelet activity was lowered by inactivating the integrin αIIb/β3 and reducing the binding of fibrinogen. Furthermore, the effect of G-Rk3 extended to the inhibition of MAPK and PI3K/Akt phosphorylation resulting in the reduced secretion of intracellular granules and reduced production of TXA2. Lastly, G-Rk3 inhibited platelet aggregation and thrombus formation via fibrin clot. Conclusions and implications: These results suggest that when dealing with cardiovascular diseases brought upon by faulty aggregation among platelets or through the formation of a thrombus, the G-Rk3 compound can play a role as an effective prophylactic or therapeutic agent.