• Title/Summary/Keyword: structural protein

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Physicochemical Properties of Sugary-Endosperm Mutants in Rice (벼 고당미 변이계통 배유의 이화학적 특성)

  • ;Mun-Hue Heu
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.39 no.1
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    • pp.1-6
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    • 1994
  • Some physicochemical properties of sugary rices were comparatively analyzed with the original cultivars, using Hwachung su-1, su-2, and Nampung su lines bred in Seoul Nat'l Univ., and EM 5 bred in Kyushu Univ. Sugary rice grains were smaller in width and thickness, and the relative dry weight of 1000 grains of sugary rices ranged from 49% to 72%, compared to normal ones. No distinct starch granules were found in endosperm of sugary rices exposured by SEM, with structural variations between Hwachung su-1 and su-2 lines. Sugary rices showed the significant increases in sucrose, glucose and fructose content, especially much higher in sucrose content showing 5.84-8.79%, in comparison with the normal ones, 1.11∼2.65%. However, sucrose and total sugar content varied within sugary lines carrying the same sugary gene, and were significantly lower in Hwachung su-2. Sugary rices, except Hwachung su-1, showed the same or lower ADV and harder gel characteristics, compared to normal ones. Protein and lipid content were much higher in sugary rices, due to the increased relative proportion of aleurone layer in brown rice caused by thicker aleurone layer than in normal rices and the reduction of endosperm part. However, there were no remarkable changes in amino acid and fatty acid compositions.

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Anti-Proliferative and Pro-Apoptotic Activities of 4-Methyl-2,6-bis(1-phenylethyl)phenol in Cancer Cells

  • Sung, Nak Yoon;Kim, Seung Cheol;Kim, Yun Hwan;Kim, Gihyeon;Lee, Yunmi;Sung, Gi-Ho;Kim, Ji Hye;Yang, Woo Seok;Kim, Mi Seon;Baek, Kwang-Soo;Kim, Jong-Hoon;Cho, Jae Youl
    • Biomolecules & Therapeutics
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    • v.24 no.4
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    • pp.402-409
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    • 2016
  • It has been found that 4-isopropyl-2,6-bis(1-phenylethyl)phenol (KTH-13), a novel compound isolated from Cordyceps bassiana, is able to suppress tumor cell proliferation by inducing apoptosis. To mass-produce this compound, we established a total synthesis method. Using those conditions, we further synthesized various analogs with structural similarity to KTH-13. In this study, we aimed to test their anti-cancer activity by measuring anti-proliferative and pro-apoptotic activities. Of 8 compounds tested, 4-methyl-2,6-bis(1-phenylethyl)phenol (KTH-13-Me) exhibited the strongest anti-proliferative activity toward MDA-MB 231 cells. KTH-13-Me also similarly suppressed the survival of various cancer cell lines, including C6 glioma, HCT-15, and LoVo cells. Treatment of KTH-13-Me induced several apoptotic signs in C6 glioma cells, such as morphological changes, induction of apoptotic bodies, and nuclear fragmentation and chromatin condensation. Concordantly, early-apoptotic cells were also identified by staining with FITC-Annexin V/PI. Moreover, KTH-13-Me highly enhanced the activation of caspase-3 and caspase-9, and decreased the protein level of Bcl-2. In addition, the phosphorylation levels of Src and STAT3 were diminished in KTH-13-Me-treated C6 cells. Therefore, these results suggest that KTH-13-Me can be developed as a novel anti-cancer drug capable of blocking proliferation, inducing apoptosis, and blocking cell survival signaling in cancer cells.

Extraction of Glycosaminoglycan from Sea Hare, Aplysia kurodai, and Its Functional Properties 2. Structural Properties of Purified Glycosaminoglycan (군소(Aplysia kurodai)에 분포하는 글루코사미노글리칸의 추출과 기능특성 2. 글루코사미노글리칸의 구조 특성)

  • Yoon, Bo-Yeong;Choi, Byeong-Dai;Bae, Dong-Won;Choi, Yeung-Joon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.11
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    • pp.1647-1653
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    • 2010
  • Glycosaminoglycan (GAG) was purified from polysaccharide extracted from sea hare muscle on DEAE-Sepharose column and investigated for the functional groups, distribution of sugars, composition of disaccharide and structure of GAG. Purified GAG was composed of disaccharide above 55% of total sugar. Purified GAG showed amide I peak in 1648/cm and C-O stretch peak as properties of carbohydrate, amino acid peak in 1457/cm, and peak in 866/cm as properties of monosaccharide by FT-IR. Fucose, N-acetylgalactosamine, N-acetylglucosamine, glucose, galactose, mannose and xylose were found in MALDI-TOF MS/MS spectra of hydrolysates by chondroitin sulfate ABC lyase and heparanase I. Purified GAG was expected to be heparan sulfate including N-acetylgalactosamine and N-acetylglucosamine above 70% of total sugar. The structure of GAG was supposed as GlyUA(2S)-GlcNS and GlyUA-GlcNS(6S) with O-linkage on protein core.

Neuronal injury in AIDS dementia: Potential treatment with NMDA open-channel blockers and nitric oxide-related species

  • Lipton, Stuart A.
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.04a
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    • pp.19-29
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    • 1996
  • The neurological manifestations of AIDS include dementia, encountered even in the absence of opportunistic superinfection or malignancy. The AIDS Dementia Complex appears to be associated with several neuropathological abnormalities, including astrogliosis and neuronal injury or loss. How can HIV-1 result in neuronal damage if neurons themselves are only rarely, if ever, infected by the vitus\ulcorner In vitro experiments from several different laboratiories have lent support to the existence of HIV- and immune-related toxins. In one recently defined pathway to neuronal injury, HIV-infected macrophages/microglia as well as macrophages activated by HIV-1 envelope protein gp120 appear to secrete excitants/neurotoxins. These substances may include arachidonic acid, platelet-activating factor, free radicals (NO - and O$_2$), glutamate, quinolinate, cysteine, cytokines (TNF-${\alpha}$, IL1-B, IL-6), and as yet unidentified factors emanating from stimulated macrophages and possibly reactive astrocytes. A final common pathway for newonal suscepubility appears to be operative, similar to that observed in stroke, trauma, epilepsy, and several neurodegenerative diseases, including Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis. This mechanism involves excessive activation of N-methyl-D-aspartate (NMDA) receptor-operated channels, with resultant excessive influx of Ca$\^$2+/ leading to neuronal damage, and thus offers hope for future pharmacological intervention. This chapter reviews two clinically-tolerated NMDA antagonists, memantine and nitroglycerin; (ⅰ) Memantine is an open-channel blocker of the NMDA-associated ion channel and a close congener of the anti-viral and anti-parkinsonian drug amantadine. Memantine blocks the effects of escalating levels of excitotoxins to a greater degree than lower (piysiological) levels of these excitatory amino acids, thus sparing to some extent normal neuronal function. (ⅱ) Niuoglycerin acts at a redox modulatory site of the NMDA receptor/complex to downregulate its activity. The neuroprotective action of nitroglycerin at this site is mediated by n chemical species related to nitric oxide, but in a higher oxidation state, resulting in transfer of an NO group to a critical cysteine on the NMDA receptor. Because of the clinical safety of these drugs, they have the potential for trials in humans. As the structural basis for redox modulation is further elucidated, it may become possible to design even better redox reactive reagents of chinical value. To this end, redox modulatory sites of NMDA receptors have begun to be characterized at a molecular level using site-directed mutagenesis of recombinant subunits (NMDAR1, NMDAR2A-D). Two types of redox modulation can be distinguished. The first type gives rise to a persistent change in the functional activity of the receptor, and we have identified two cysteine residues on the NMDARI subunit (#744 and #798) that are responsible for this action. A second site, presumably also a cysteine(s) because <1 mM N-ethylmaleimide can block its effect in native neurons, underlies the other, more transient redox action. It appears to be at this, as yet unidentified, site on the NMDA receptor that the NO group acts, at least in recombinant receptors.

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Action and Signaling of Lysophosphatidylethanolamine in MDA-MB-231 Breast Cancer Cells

  • Park, Soo-Jin;Lee, Kyoung-Pil;Im, Dong-Soon
    • Biomolecules & Therapeutics
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    • v.22 no.2
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    • pp.129-135
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    • 2014
  • Previously, we reported that lysophosphatidylethanolamine (LPE), a lyso-type metabolite of phosphatidylethanolamine, can increase intracellular $Ca^{2+}$ ($[Ca^{2+}]_i$) via type 1 lysophosphatidic acid (LPA) receptor ($LPA_1$) and CD97, an adhesion G-protein-coupled receptor (GPCR), in MDA-MB-231 breast cancer cells. Furthermore, LPE signaling was suggested as like $LPA_1/CD97-G_{i/o}$ proteins-phospholipase $C-IP_3-Ca^{2+}$ increase in these cells. In the present study, we further investigated actions of LPE not only in the $[Ca^{2+}]_i$ increasing effect but also in cell proliferation and migration in MDA-MB-231 breast cancer cells. We utilized chemically different LPEs and a specific inhibitor of $LPA_1$, AM-095 in comparison with responses in SK-OV3 ovarian cancer cells. It was found that LPE-induced $Ca^{2+}$ response in MDA-MB-231 cells was evoked in a different manner to that in SK-OV3 cells in terms of structural requirements. AM-095 inhibited LPE-induced $Ca^{2+}$ response and cell proliferation in MDA-MB-231 cells, but not in SK-OV3 cells, supporting $LPA_1$ involvement only in MDA-MB-231 cells. LPA had significant effects on cell proliferation and migration in MDA-MB-231 cells, whereas LPE had less or no significant effect. However, LPE modulations of MAPKs (ERK1/2, JNK and p38 MAPK) was not different to those by LPA in the cells. These data support the involvement of LPA1 in LPE-induced $Ca^{2+}$ response and cell proliferation in breast MDA-MB-231 cells but unknown GPCRs (not $LPA_1$) in LPE-induced responses in SK-OV3 cells. Furthermore, although LPE and LPA utilized $LPA_1$, LPA utilized more signaling cascades than LPE, resulting in stronger responses by LPA in proliferation and migration than LPE in MDA-MB-231 cells.

Gene Cluster Analysis and Functional Characterization of Cyclomaltodextrinase from Listeria innocua (Listeria innocua 유래 cyclomaltodextrinase의 유전자 클러스터 구조 및 효소 특성)

  • Jang, Myoung-Uoon;Jeong, Chang-Ku;Kang, Hye-Jeong;Kim, Min-Jeong;Lee, Min-Jae;Son, Byung Sam;Kim, Tae-Jip
    • Microbiology and Biotechnology Letters
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    • v.44 no.3
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    • pp.363-369
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    • 2016
  • A putative cyclomaltodextrinase gene (licd) was found from the genome of Listeria innocua ATCC 33090. The licd gene is located in the gene cluster involved in maltose/maltodextrin utilization, which consists of various genes encoding maltose phosphorylase and sugar ABC transporters. The structural gene encodes 591 amino acids with a predicted molecular mass of 68.6 kDa, which shares less than 58% of amino acid sequence identity with other known CDase family enzymes. The licd gene was cloned, and the dimeric enzyme with C-terminal six-histidines was successfully produced and purified from recombinant Escherichia coli. The enzyme showed the highest activity at pH 7.0 and 37℃. licd could hydrolyze β-cyclodextrin, starch, and maltotriose to mainly maltose, and it cleaved pullulan to panose. It could also catalyze the hydrolysis of acarbose to glucose and acarviosine-glucose. In particular, it showed significantly higher activity towards β-cyclodextrin and maltotriose than towards starch and acarbose. licd also showed transglycosylation activity, producing α-(1,6)- and/or α-(1,3)-linked transfer products from the acarbose donor and α-methyl glucopyranoside acceptor.

Bovine Growth Hormone and Milk Fat Synthesis: from the Body to the Molecule - Review -

  • Kim, W.Y.;Ha, J.K.;Han, In K.;Baldwin, R.L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.10 no.4
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    • pp.335-356
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    • 1997
  • Injection of bovine growth hormone (bGH) to lactating dairy cows increases milk yield and yields of milk components including fat. It is generally believed that most of the anabolic effects derived from bGH in animal tissues are primarily mediated by IGF-1. IGF-1 is a strong anabolic peptide in the plasma of animals and exerts mitogenic and metabolic effects on target cells. Contrary to most protein hormones, the majority of IGF-1 in circulation is bound to the binding proteins (IGFBPs) which are known to be responsible for modifying the biological actions of IGF-1, thus making determinations of IGF-1 actions more difficult. On the other hand, fat is a major milk component and the greatest energy source in milk. Currently, the fat content of milk is one of the major criteria used in determining milk prices. It has been known that flavor and texture of dairy products are mainly affected by milk fat and its composition. Acetyl-CoA carboxylase (ACC) is the rate limiting enzyme which catalyzes the conversion of acetyl-CoA to malonyl-CoA for fatty acid synthesis in 1ipogenic tissues of animals including bovine lactating mammary glands. In addition to the short-tenn hormonal regulation of ACC by changes in the catalytic efficiency per enzyme molecule brought about by phosphorylation and dephosphorylation of the enzyme, the long-term hormonal regulation of ACC by changes in the number of enzyme molecules plays an essential role in control of ACC and lipogenesis. Insulin, at supraphysiological concentrations, binds to IGF-1 receptors, thereby mimicking the biological effects of IGF-1. The receptors for insulin and IGF-1 share structural and functional homology. Furthermore, epidermal growth factor increased ACC activity in rat hepatocytes and adipocytes. Therefore, it can be assumed that IGF-1 mediating bGH action may increase milk fat production by stimulation ACC with phosphorylation (short term) and/or increasing amounts of the enzyme proteins (long term). Consequently, the main purpose of this paper is to give the readers not only the galactopoietic effects of bGH, but also the insight of bGH action with regard to stimulating milk fat synthesis from the whole body to the molecular levels.

Clonig of CM-cellulase Gene of Rhizobium meliloti TAL1372 in Escherichia coli (Rhizobium meliloti TAL1372에서 섬유소분해효소 유전자 클로닝)

  • Park, Yong-Woo;Lim, Sun-Teak;Kang, Kyu-Young;Yun, Han-Dae
    • Applied Biological Chemistry
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    • v.38 no.4
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    • pp.313-319
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    • 1995
  • The involvement of the cell-wall degrading enzymes in Rhizobium has long been an unsolved question about the infection process in the formation of root nodule. To assess the contribution of the cellulase to the nodulation of rhzobia, here we report the production of cellulase from R. meliloti TAL1372 which degrade carboxymethylcellulose (CMC) model substrate with CMC-plate method. We constructed a genomic library by cloning Sau3A-digested genomic DNA from R. meliloti TAL1372 into the BamHI site of the cosmid vector pLAFR3. Out of more than one thousand transductants of E. coli, one clone (pRC8-71) had CM-cellulase activity and contained pLAFR3 cosmid with 30 kb insert of R. meliloti DNA The product of CM-cellulase gene was analyzed by native PAGE. About 45 kD protein was considered to be a product of the gene. Tn5 mutagenesis reveals that the structural gene located in a ca. 3 kb KpnI fragment. The cellulase-minus mutants of R. meliloti TAL1372 were obtained by Tn5 mutagenesis of pRC8-71 and marker exchange techniques. Analyses of the nodulation ability of these Tn5 mutants showed that the CM-cellulase gene of R. meliloti TAL1372 may be involved in early nodulation development on alfalfa (Medicago satiua).

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Identification and Characterization of a New Alkaline SGNH Hydrolase from a Thermophilic Bacterium Bacillus sp. K91

  • Yu, Tingting;Ding, Junmei;Zheng, Qingxia;Han, Nanyu;Yu, Jialin;Yang, Yunjuan;Li, Junjun;Mu, Yuelin;Wu, Qian;Huang, Zunxi
    • Journal of Microbiology and Biotechnology
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    • v.26 no.4
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    • pp.730-738
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    • 2016
  • est19 is a gene from Bacillus sp. K91 that encodes a new esterase. A comparison of the amino acid sequence showed that Est19 has typical Ser-Gly-Asn-His (SGNH) family motifs and could be grouped into the SGNH hydrolase family. The Est19 protein was functionally cloned, and expressed and purified from Escherichia coli BL21(DE3). The enzyme activity was optimal at 60℃ and pH 9.0, and displayed esterase activity towards esters with short-chain acyl esters (C2-C6). A structural model of Est19 was constructed using phospholipase A1 from Streptomyces albidoflavus NA297 as a template. The structure showed an α/β-hydrolase fold and indicated the presence of the typical catalytic triad Ser49-Asp227-His230, which were further investigated by site-directed mutagenesis. To the best of our knowledge, Est19 is a new member of the SGNH hydrolase family identified from thermophiles, which may be applicable in the industrial production of semisynthetic β-lactam antibiotics after modification.

Anti-wrinkle Effect of Safflower (Carthamus tinctorius L.) Seed Extract (II) (홍화씨추출물의 피부 주름개선 효과(II))

  • Kim Mi Jin;Kim Ja Young;Choi Sang-Won;Hong Jin Tae;Yoon Kyung-Sup
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.30 no.4 s.48
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    • pp.449-456
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    • 2004
  • Phytoestrogens derived from plants and foods, which are diphenolic compounds with structural similarities to natural and synthetic estrogens, have been shown to estrogenic and antiestrogenic actions. Particularly, recent study revealed that phenolic compounds in safflower seed, such as serotonin derivatives, lignans and flavonoids, could be acted as phytoestrogens. Safflower (Carthamus tinctorius L.) seed extract (SID C.SE), therefore, are receiving a renewed interest as potential therapeutic source against skin wrinkles induced by estrogen deficiency. This study was conducted to investigate the anti-wrinkle effect of SID C.SE on normal human fibroblasts through the expression of type I procollagen and UVA-induced MMP-1 in vitro. The SID C.SE increased the type I procollagen expression, comparable to trans-retinol and reduced UVA-induced MMP-1 expression in a dose-dependent manner. The clinical study indicated that cream group treated with $0.1\%$ SID C.SE significantly reduced a skin wrinkles, as compared with a control (non-treated cream group) (p<0.05). These results suggest that the safflower seed extract may be useful as potential source of anti-wrinkle cosmetics.