• 제목/요약/키워드: Lipid Binding

검색결과 431건 처리시간 0.031초

An NMR Study on the Conformation of Substance P in Acidic Bicelles

  • Baek, Seung-Bin;Lim, Sung-Chul;Lee, Hyeong-Ju;Lee, Hee-Cheon;Kim, Chul
    • Bulletin of the Korean Chemical Society
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    • 제32권10호
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    • pp.3702-3706
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    • 2011
  • The conformation of a neuropeptide, substance P (SP), in isotropic (q = 0.5) acidic bicelles was investigated using two-dimensional NMR techniques. By the nuclear Overhauser effect (NOE) cross peaks between SP and long-chain lipid molecules SP was probed to bind on the flat surface of the disc-like bicelles. Structural analysis of NMR data indicated that the helical conformation of SP extended to the C-terminal region of Leu10 as well as in the mid-region from Pro4 to Phe8. As compared with the conformations of SP bound on the sodium dodecylsulfate (SDS) or the dodecylphosphocholine (DPC) micelles with curved surfaces, the surface curvature of the membrane mimics was found to be one of the major factors inducing the biologically relevant conformation of SP. The negative surface charge of the membrane is also a key factor inducing both the binding of SP on the membrane and its biologically active structure.

Dual positional substrate specificity of rice allene oxide synthase-1: insight into mechanism of inhibition by type II ligand imidazole

  • Yoeun, Sereyvath;Rakwal, Randeep;Han, Oksoo
    • BMB Reports
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    • 제46권3호
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    • pp.151-156
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    • 2013
  • Phylogenetic and amino acid sequence analysis indicated that rice allene oxide synthase-1 (OsAOS1) is CYP74, and is clearly distinct from CYP74B, C and D subfamilies. Regio- and stereo-chemical analysis revealed the dual substrate specificity of OsAOS1 for (cis,trans)-configurational isomers of 13(S)- and 9(S)-hydroperoxyoctadecadienoic acid. GC-MS analysis showed that OsAOS1 converts 13(S)- and 9(S)-hydroperoxyoctadecadi(tri)enoic acid into their corresponding allene oxide. UV-Visible spectral analysis of native OsAOS1 revealed a Soret maximum at 393 nm, which shifted to 424 nm with several clean isobestic points upon binding of OsAOS1 to imidazole. The spectral shift induced by imidazole correlated with inhibition of OsAOS1 activity, implying that imidazole may coordinate to ferric heme iron, triggering a heme-iron transition from high spin state to low spin state. The implications and significance of a putative type II ligand-induced spin state transition in OsAOS1 are discussed.

지실 추출물의 전사인자 SREBP-1 활성에 의한 지질 생성 촉진 (Ponciri Fructus Extract Induces Lipogenesis through Transcription Factor SREBP-1 Activation)

  • 김대성;전병국;문연자;이강태;이건국;우원홍
    • 약학회지
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    • 제56권4호
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    • pp.268-273
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    • 2012
  • This study was to explore the lipogenic effect by ethanol extract of ponciri fructus (EPF) and possible molecular mechanisms in sebocyte. When SZ95 sebocyte cell line were treated with the EPF, lipid droplets were accumulated in the majority of cells. EPF increased expression of sterol regulatory element-binding protein-1 (SREBP-1) and fatty acid synthase (FAS) in the SZ95 cells. EPF augmented expression of PPAR-${\beta}$ and PPAR-${\gamma}$ but not that of PPAR-${\alpha}$. These results suggest that EPF induces lipogenesis in SZ95 cells through SREBP-1, PPAR-${\beta}$ and PPAR-${\gamma}$ activations.

Identification and Expression Analysis of Chloroplast p-psbB Gene Differentially Expressed in Wild Ginseng

  • Kim, Doo-Young;Kwon, Ki-Rok;Kang, Won-Mo;Jeon, Eun-Yi;Jang, Jun-Hyeog
    • 대한약침학회지
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    • 제15권1호
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    • pp.18-22
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    • 2012
  • Panax ginseng is a well-known herbal medicine in traditional Asian medicine. Although wild ginseng is widely accepted to be more active than cultivated ginseng in chemoprevention, little has actually been reported on the difference between wild ginseng and cultivated ginseng. Using suppressive subtraction hybridization, we cloned the p-psbB gene as a candidate target gene for a wild ginseng-specific gene. Here, we report that one of the clones isolated in this screen was the chloroplast p-psbB gene, a chlorophyll a-binding inner antenna protein in the photosystem II complex, located in the lipid matrix of the thylakoid membrane. Real-time results showed that the expression of the p-psbB gene was significantly up-regulated in wild ginseng as compared to cultivated ginseng. Thus, the p-psbB gene may be one of the important markers of wild ginseng.

수침과 입자크기를 달리한 쌀가루와 쌀 만주제조 특성 (Characteristics of Preparation of Rice Manju and Rice Flour with Soaking and Different Particle Sizes)

  • 이승현;신말식
    • 한국식품조리과학회지
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    • 제25권4호
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    • pp.427-434
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    • 2009
  • To increase rice consumption and substitute rice flour for wheat flour to make gluten-free bakery products, the physicochemical and pasting properties of rice flours prepared from raw and soaked rices passed through different size screens were investigated. The quality properties of manju dough and preparation of rice manju were also measured. Dry milled flour with soaked rice (DMFSR) were decreased in ash and crude lipid contents compared to dry milled flour with raw rice (DMFRR). Water binding capacity, damaged starch content, and L value of rice flour increased with decreasing particle size, but the b value decreased. Peak, cold, and breakdown viscosities of DMFSR were higher than those of DMFRR by RVA. Hardness of manju dough with DMFSR was lower than that with DMFRR, but that of manju shell exhibited a reverse trend. Sensory difference testing revealed the smoothness of surface, hardness, roughness, and overall quality were significantly different (p<0.05). The smoothness of the surface of manju with DMFRR-200 and all DMFSR were better than that of manju prepared with wheat flour. Hardness showed lower values in DMFRR-200, and all DMFSR as well as wheat flour and roughness decreased with decreasing particle size. Rice manju with wheat flour, DMFRR-200, DMFSR-120, and DMFSR-170 ranked above 5 points and were not significantly different (p<0.05).

Anti-adipocyte differentiation activity and flavonoid content determination by HPLC/UV analysis of tree sprouts

  • Kim, Juree;Jang, Taewon;Kim, Ji Hyun;Shin, Hanna;Park, Jaeho;Lee, Sanghyun
    • Journal of Applied Biological Chemistry
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    • 제64권3호
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    • pp.269-275
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    • 2021
  • The in vitro anti-obesity activity of 12 species of tree sprouts in differentiated 3T3-L1 cells and the mechanisms underlying their activity were evaluated. (+)-Catechin and quercetin concentrations in the sprouts were analyzed by HPLC/UV at 270 and 254 nm, respectively. Euonymus alatus (EAT) and Fraxinus mandschuria (FMS) extracts at doses of 50 and 100 ㎍/mL inhibited the accumulation of lipid droplets in differentiated 3T3-L1 cells. Moreover, EAT and FMS downregulated the expression of the CCAAT/enhancer-binding protein-α, adipogenesis-related proteins peroxisome proliferator-activated receptor-γ, and adipocyte P-2α in differentiated 3T3-L1 cells. Tree sprouts with an abundant flavonoid content exerted the highest anti-obesity activity. Concentrations of total flavonoids were the highest in FMS (24.281 mg/g DW) sprouts. These findings could be used to develop health-promoting functional foods or supplements derived from tree sprouts.

Increased Hepatic Lipogenesis Elevates Liver Cholesterol Content

  • Berger, Jean-Mathieu;Moon, Young-Ah
    • Molecules and Cells
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    • 제44권2호
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    • pp.116-125
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    • 2021
  • Cardiovascular diseases (CVDs) are the most common cause of death in patients with nonalcoholic fatty liver disease (NAFLD) and dyslipidemia is considered at least partially responsible for the increased CVD risk in NAFLD patients. The aim of the present study is to understand how hepatic de novo lipogenesis influences hepatic cholesterol content as well as its effects on the plasma lipid levels. Hepatic lipogenesis was induced in mice by feeding a fat-free/high-sucrose (FF/HS) diet and the metabolic pathways associated with cholesterol were then analyzed. Both liver triglyceride and cholesterol contents were significantly increased in mice fed an FF/HS diet. Activation of fatty acid synthesis driven by the activation of sterol regulatory element binding protein (SREBP)-1c resulted in the increased liver triglycerides. The augmented cholesterol content in the liver could not be explained by an increased cholesterol synthesis, which was decreased by the FF/HS diet. HMG-CoA reductase protein level was decreased in mice fed an FF/HS diet. We found that the liver retained more cholesterol through a reduced excretion of bile acids, a reduced fecal cholesterol excretion, and an increased cholesterol uptake from plasma lipoproteins. Very low-density lipoproteintriglyceride and -cholesterol secretion were increased in mice fed an FF/HS diet, which led to hypertriglyceridemia and hypercholesterolemia in Ldlr-/- mice, a model that exhibits a more human like lipoprotein profile. These findings suggest that dietary cholesterol intake and cholesterol synthesis rates cannot only explain the hypercholesterolemia associated with NAFLD, and that the control of fatty acid synthesis should be considered for the management of dyslipidemia.

Isolation of the ppar-${\gamma}$ ligands from the stem of the Zanthoxylum Schinifolium and their structure activity relationships

  • Nam, Jeong-Bum;Lee, Jeong-Hyung;Kim, Young-Ho;Lee, Jung-Joon
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.380.2-380.2
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    • 2002
  • Peroxisome proliferator-activated receptor (PPAR)-$\gamma$ is a nuclear hormone receptor family that plays an important role in the transcriptional regulation of genes in cellular lipid and energy metabolism. In our search for Iigands for PPAR-$\gamma$ from natural resources. two phenylpropanoids. 3.4.5-Trimethoxy cinnamylalcohol (1) and 3.4.5- Trimethoxy cinnamaldehyde (2). were isolated as PPAR-$\gamma$ agonists from the MeOH extracts of Zanthoxylum schinifolium Sieb. & ZUCCo (Rutaceae) by activity-guided fractionation. These two compoundS bind and activated PPAR-$\gamma$ transcriptional activity in a dose dependent manner assessed by ligand-binding assay. While the maximum activities for PPAR-$\gamma$ of these compounds were comparable with that of rosiglitazone. which is currently used in the treatment of Type II diabetes. the potency of these compounds were much weaker than rosiglitazone ($ED_{50}$=t.2$\mu\textrm{M}$) with the $ED_{50}$ values of 9.08 and 4.08 $\mu\textrm{M}$. respectively. To examine the structure-activity relationship of phenylpropanoids. we prepared several phenylpropanoid derivatives and measured the activity. We observed that substituents at 4'- position could playa key role in determining the potency for PPAR-$\gamma$ agonistic activity .

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Bioconversion Products of Whey by Lactic Acid Bacteria Exert Anti-Adipogenic Effect

  • Lee, Ji Soo;Hyun, In Kyung;Yoon, Ji-Won;Seo, Hye-Jin;Kang, Seok-Seong
    • 한국축산식품학회지
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    • 제41권1호
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    • pp.145-152
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    • 2021
  • Microbial bioconversion using lactic acid bacteria (LAB) provides several human health benefits. Although whey and whey-derived bioactive compounds can contribute to an improvement in human health, the potential anti-obesity effect of whey bioconversion by LAB has not been well studied. This study aimed to investigate whether bioconversion of whey by Pediococcus pentosaceus KI31 and Lactobacillus sakei KI36 (KI31-W and KI36-W, respectively) inhibits 3T3-L1 preadipocyte differentiation. Both KI31-W and KI36-W reduced intracellular lipid accumulation significantly, without decreasing 3T3-L1 preadipocyte proliferation. In addition, obesity-related transcription factor (peroxisome proliferator-activated receptor γ) and genes (adipocyte fatty acid-binding protein and lipoprotein lipase) were down-regulated significantly in 3T3-L1 cells in the presence of KI31-W and KI36-W. Collectively, these results suggest that bioconversion of whey by LAB exhibits anti-adipogenic activity and may be applied as a therapeutic agent for obesity.

Myricetin Disturbs the Cell Wall Integrity and Increases the Membrane Permeability of Candida albicans

  • Lee, Heung-Shick;Kim, Younhee
    • Journal of Microbiology and Biotechnology
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    • 제32권1호
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    • pp.37-45
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    • 2022
  • The fungal cell wall and membrane are the principal targets of antifungals. Herein, we report that myricetin exerts antifungal activity against Candida albicans by damaging the cell wall integrity and notably enhancing the membrane permeability. In the presence of sorbitol, an osmotic protectant, the minimum inhibitory concentration (MIC) of myricetin against C. albicans increased from 20 to 40 and 80 ㎍/ml in 24 and 72 h, respectively, demonstrating that myricetin disturbs the cell wall integrity of C. albicans. Fluorescence microscopic images showed the presence of propidium iodide-stained C. albicans cells, indicating the myricetin-induced initial damage of the cell membrane. The effects of myricetin on the membrane permeability of C. albicans cells were assessed using crystal violet-uptake and intracellular material-leakage assays. The percentage uptakes of crystal violet for myricetin-treated C. albicans cells at 1×, 2×, and 4× the MIC of myricetin were 36.5, 60.6, and 79.4%, respectively, while those for DMSO-treated C. albicans cells were 28.2, 28.9, and 29.7%, respectively. Additionally, myricetin-treated C. albicans cells showed notable DNA and protein leakage, compared with the DMSO-treated controls. Furthermore, treatment of C. albicans cells with 1× the MIC of myricetin showed a 17.2 and 28.0% reduction in the binding of the lipophilic probes diphenylhexatriene and Nile red, respectively, indicating that myricetin alters the lipid components or order in the C. albicans cell membrane, leading to increased membrane permeability. Therefore, these data will provide insights into the pharmacological worth of myricetin as a prospective antifungal for treating C. albicans infections.