• 제목/요약/키워드: Biological Synthesis

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Identification of a Domain in Yeast Chitin Synthase 3 Required for Biogenesis of Chitin Ring, But Not Cellular Chitin Synthesis

  • Park Hyun-Sook;Park Mee-Hyun;Kim Chi-Hwa;Woo Jeeun;Lee Jee-Yeon;Kim Sung-Uk;Choi Wonja
    • 한국미생물학회:학술대회논문집
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    • 한국미생물학회 2000년도 추계학술발표대회
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    • pp.39-45
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    • 2000
  • It hab been proposed that CHS3-mediated chitin synthesis during the vegitative cell cycle is regulated by CHS4. To investigate direct protein-protein interaction between their coding products, we used yeast two hybrid system and found that a domain of Chs3p was responsible for interaction with Chs4p. This domain, termed MIRC3-4 (maximum interacting region of chs3p with chs4p), spans from 647 to 700 residues. It is well conserved among CHS3 homologs of various fungi such as Candida albicans, Emericella nidulans, Neurospora crassa, Magnaporthe grisea, Ustilago maydis, Glomus versiforme, Exophiala dermatitidis, Rhizopus microsporus. A series of mutaion in the MIRC3-4 resulted in no appearance of chitin ring at the early G 1 phase but did not affect chitin synthesis in the cell wall after cytokinesis. Absence of chitin ring could be caused either by delocalization of Chs3p to the septum or by improper interaction with Chs4p. To discriminate those two, not mutually exclusive, alternatives, mutants cells were immunostained with Chs3p-specific antibody. Some exhibited localization of chs3p to the septum, while others failed. These results indicate that simultaneous localization and activation Chs3p by Chs4p is required for chitin ring synthesis.

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Synthesis and Biological Activity of Aspirin Derivatives

  • Cha, Bae-Cheon;Lee, Seung-Bae
    • Archives of Pharmacal Research
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    • 제23권2호
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    • pp.116-120
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    • 2000
  • Aspirin has been widely used as analgesic and anti-inflammatory drug. Recently, it was elucidated that aspirin have anti-coaggregatory effect in low dose. This study was carried out to investigate the synthesis of aspirin derivatives from aspirin and aromatic compound of antioxidant and its biological activities. Synthesis of aspirin derivatives was prepared by esterification in the presence of 1, 1-carbonyldiimidazole. Biological activities was examined using effect of anti-coagulant on bleeding time, effect of antioxidant and effect of anti-platelet aggregation. As a result, SJ-101 showed strong antioxidative activity and anti-coagulant activity among four compounds. Anti-platelet aggregation of SJ-101 was examined by collagen, ADP, PAF method. SJ-101 exhibited more stronger activity to aspirin at collagen aggregation reaction. These finding demonstrates that SJ-101 is usefull as care drug of aging and old-disease because of its has antioxidant activity, anti-coagulant activity and anti-platelet activity.

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Enzymatic Synthesis of Sorbitan Methacrylate: Effect of Acyl donor and Molar ratio

  • Lee, Hye-Jin;Jeong, Gwi-Taek;Lee, Kyoung-Min;Ryu, Hwa-Won;Kim, Do-Man;Park, Don-Hee;Kim, Hae-Sung
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2005년도 생물공학의 동향(XVI)
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    • pp.296-299
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    • 2005
  • Sugar polymers have been considered as biomaterial. Biomaterials are widely utilized for a medical applications in direct contact with living tissue Clearly, biomaterials must be carefully and microscopically fabricated for optimal acceptance within the living organism in both functional and structural senses. In this study, the enzymatic synthesis of sorbitan methacrylate from 1,4-sorbitan via the manipulation of an immobilized biocatalyst (Novozym 435) and acryl donors (methacrylic acid and vinyl methacrylate) was evaluated.

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키토산 C-6에 Amine기를 갖는 Polyamino Acid 유도체의 합성과 생물학적 활성에 관한 연구 (A Study on the Synthesis and Biological Activity of Polyamino Acid Derivatives have Amine Group on to Chitosan C-6)

  • 류성렬
    • 한국응용과학기술학회지
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    • 제28권4호
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    • pp.438-448
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    • 2011
  • Chitosan is widely used in cosmetics and medical fields. Special emphasis has been put on the chemical modification of chitosan to explore its full potential. We have described the synthesis and biological activity of novel peptide amino acid derivatives. The polyamino acid derivatives were synthesized by introducing alkylamine functional group on chitosan at C-6. The poor aqueous solubility of chitosan derivatives hinder both pharmacological studies and pharmaceutical development. To make amino acid coupled chitosan derivatives with improved biological effect and solubility, some attempts have been taken to consist of amino peptide group like aspartic acid and phenylalanine-aspartic acid derivatives onto chitosan C-6. The resultingly substituted chitosan was characterized by solubility in various solvents. We measured chitosan derivatives with $^1H$-NMR and $^{13}C$-NMR. Also, We were investigated on the physical properties and biological activities of these products.

EFFECTS OF HIGH BY-PRODUCT DIETS CONTAINING RICE BRAN AND BEET PULP ON THE SITE AND EXTENT OF DIGESTION AND MICROBIAL SYNTHESIS IN STEERS

  • Zhao, Y.;Taniguchi, K.;Obitsu, T.
    • Asian-Australasian Journal of Animal Sciences
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    • 제9권6호
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    • pp.655-665
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    • 1996
  • The effects of feeding rice bran and beet pulp mixtures on the site and extent of digestion and microbial synthesis in fattening steers were studied. Three Holstein steers fitted with ruminal, duodenal and ileal cannulas were fed four diets in a $4{\times}3$ Youden square design. The four diets consisted of 15% Italian ryegrass hay and 85% concentrate as a control diet which included 72% rolled barley, 20% rice bran plus 40% beet pulp, 30% rice bran plus 30% beet pulp or 40% rice bran plus 20% beet pulp. All diets provided 1.8 times digestible energy required for maintenance. The digestibility of fat in the small intestine (% of flow) showed an increase with rice bran content among the by-product diets. Digestibility of structural carbohydrate both in the rumen and the whole digestive tract decreased linearly with rice bran content. The digestibility of nonstructural carbohydrate was not affected by rice bran content, but that of nonstructural, nonstarch polysaccharides was higher in the rumen and lower in the large intestine for the by-product diets than for the control diet. A rice bran content of more than 30% in the by-product diets severely inhibits ruminal microbial synthesis and digestible energy intake in fattening steers.

Effect of Intensity of Unconditional Stimulus on Reconsolidation of Contextual Fear Memory

  • Kwak, Chul-Jung;Choi, Jun-Hyeok;Bakes, Joseph T.;Lee, Kyung-Min;Kaang, Bong-Kiun
    • The Korean Journal of Physiology and Pharmacology
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    • 제16권5호
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    • pp.293-296
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    • 2012
  • Memory reconsolidation is ubiquitous across species and various memory tasks. It is a dynamic process in which memory is modified and/or updated. In experimental conditions, memory reconsolidation is usually characterized by the fact that the consolidated memory is disrupted by a combination of memory reactivation and inhibition of protein synthesis. However, under some experimental conditions, the reactivated memory is not disrupted by inhibition of protein synthesis. This so called "boundary condition" of reconsolidation may be related to memory strength. In Pavlovian fear conditioning, the intensity of unconditional stimulus (US) determines the strength of the fear memory. In this study, we examined the effect of the intensity of US on the reconsolidation of contextual fear memory. Strong contextual fear memory, which is conditioned with strong US, is not disrupted by inhibition of protein synthesis after its reactivation; however, a weak fear memory is often disrupted. This suggests that a US of strong intensity can inhibit reconsolidation of contextual fear memory.