• Title/Summary/Keyword: Natural Degradation

Search Result 786, Processing Time 0.027 seconds

Purification and Structure Determination of Antifungal Phospholipids from a Marine Streptomyces

  • Cho, Ki-Woong;Seo, Young-Wan;Yoon, Tae-Mi;Shin, Jong-Heon
    • Journal of Microbiology and Biotechnology
    • /
    • v.9 no.6
    • /
    • pp.709-715
    • /
    • 1999
  • A series of antifungal compounds were obtained from the methanol extract of the mycelium from marine actinomycetes M428 which was identified as a Stereptomyces species by fatty acid composition and biochemical characteristics. These compounds were purified by combined chromatographic techniques and the structures were characterized with spectroscopic methods including 1D and 2D NMR, and mass spectrometry as sn-l lysophosphatidyl inositols. The side chains were established by chemical degradation followed by GC analysis to be 14-methyl pentadecanoic acid (iso-palmitic acid, i-C16:0, compound A) and 13-methyl tetradecanoic acid (iso-pentadecanoic acid, i-C15:0, compound B). These compounds displayed highly selective antifungal activity against C. albicans with MIC values of $5{\;}\mu\textrm{g}/ml$ (compound A) and $2.5{\;}\mu\textrm{g}/ml$ (compound B), while it had almost negligible antibiotic activity against E. coli and P aerogenosa with MIC value higher than $50{\;}\mu\textrm{g}/ml$ and no cytotoxic activities against human myeloma leukemia K562 ($IC_{50}>100{\;}\mu\textrm{g}/ml$).

  • PDF

MICAL-like Regulates Fasciclin II Membrane Cycling and Synaptic Development

  • Nahm, Minyeop;Park, Sunyoung;Lee, Jihye;Lee, Seungbok
    • Molecules and Cells
    • /
    • v.39 no.10
    • /
    • pp.762-767
    • /
    • 2016
  • Fasciclin II (FasII), the Drosophila ortholog of neural cell adhesion molecule (NCAM), plays a critical role in synaptic stabilization and plasticity. Although this molecule undergoes constitutive cycling at the synaptic membrane, how its membrane trafficking is regulated to ensure proper synaptic development remains poorly understood. In a genetic screen, we recovered a mutation in Drosophila mical-like that displays an increase in bouton numbers and a decrease in FasII levels at the neuromuscular junction (NMJ). Similar phenotypes were induced by presynaptic, but not postsynaptic, knockdown of mical-like expression. FasII trafficking assays revealed that the recycling of internalized FasII molecules to the cell surface was significantly impaired in mical-like-knockdown cells. Importantly, this defect correlated with an enhancement of endosomal sorting of FasII to the lysosomal degradation pathway. Similarly, synaptic vesicle exocytosis was also impaired in mical-like mutants. Together, our results identify Mical-like as a novel regulator of synaptic growth and FasII endocytic recycling.

Effects of Monovalent Cations on the βReaction Kinetics of Tryptophan Synthase (트립토판 합성효소의 β반응속도에 미치는 일가양이온의 영향)

  • Kim, Il;Shin, Hye-Ja;Im, Woon-Ki;Kim, Han-Do
    • Journal of Life Science
    • /
    • v.14 no.1
    • /
    • pp.17-20
    • /
    • 2004
  • Effects of monovalent cations were examined on the fast $\beta$reaction of $\alpha$D56N and $\alpha$D56G mutant tryptophan synthase. Reaction rates for the production and degradation of intermediates in the reaction were changed in the presence of cathons. The mutant proteins showed different reaction rates from those of wild-type protein, and additional changes occurred in the presence of cations. The results showed that monovalent cations and $\alpha$D56 are important in allosteric properties of this protein.

Structural characterization of As-MIF and hJAB1 during the inhibition of cell-cycle regulation

  • Park, Young-Hoon;Jeong, Suk;Ha, Ki-Tae;Yu, Hak Sun;Jang, Se Bok
    • BMB Reports
    • /
    • v.50 no.5
    • /
    • pp.269-274
    • /
    • 2017
  • The biological activities of macrophage migration inhibitory factor (MIF) might be mediated through a classical receptor-mediated or non-classical endocytic pathway. JAB1 (C-Jun activation domain-binding protein-1) promotes the degradation of the tumor suppressor, p53, and the cyclin-dependent kinase inhibitor, p27. When MIF and JAB1 are bound to each other in various intracellular sites, MIF inhibits the positive regulatory effects of JAB1 on the activity of AP-1. The intestinal parasite, Anisakis simplex, has an immunomodulatory effect. The molecular mechanism of action of As-MIF and human JAB1 are poorly understood. In this study, As-MIF and hJAB1 were expressed and purified with high solubility. The structure of As-MIF and hJAB1 interaction was modeled by homology modeling based on the structure of Ace-MIF. This study provides evidence indicating that the MIF domain of As-MIF interacts directly with the MPN domain of hJAB1, and four structure-based mutants of As-MIF and hJAB1 disrupt the As-MIF-hJAB1 interaction.

Degradation of Acharan Sulfate and Heparin by Bacteroides stercoris HJ-15, a Human Intestinal Bacterium

  • Kim, Dong-Hyun;Kim, Byung-Taek;Park, Sun-Yong;Kim, Na-Young;Han, Myung-Joo;Shin, Kuk-Hyun;Kim, Wan-Suk;Kim, Yeong-Sik
    • Archives of Pharmacal Research
    • /
    • v.21 no.5
    • /
    • pp.576-580
    • /
    • 1998
  • When glycosaminoglycan (GAG)-degrating enzymes were measured in normal human stool suspensions, all 5 tested different stools degraded titrable heparin and acharan sulfate. GAG-degrading bacteria were screened from the isolates of human stools. Among them, HJ-15 had the most potent activities of heparinases (GAGs-degrading enzymes). However, HJ-15 produced the enzyme even if in the media without heparin. Acharan sulfate lyase was induced by acharan sulfate and heparin. Heparinase production was also induced by these GAGs. These enzymes, acharan sulfate lyase and heparinase, were produced in exponential and stationary phase of HJ-15 growth, respectively. Optimal pHs of the acharan sulfate lyase and heparinase activities were 7.2 and 7.5 respectively. the biochemical properties of HJ-15 was similar to those of B. stercoris. However, difference from B. stercoris was utilization of raffinose. this HJ-15 also degraded chondroitin sulfates A and C.

  • PDF

Biodegradation Kinetics of 4-Chlorophenol by Pseudomonas sp. EL-091S (Pseudomonas sp. EL-091S에 의한 4-Chlorophenol의 분해 Kinetics)

  • Son, Jun-Seog;Lee, Geon;Lee, Sang-Joon
    • Journal of Environmental Science International
    • /
    • v.2 no.2
    • /
    • pp.95-102
    • /
    • 1993
  • In order to find the most fitted biodegradation model, biodegradation models to the initial 4-chlorophenol concentrations were investigated and had been fitted by the linear regression. The degrading bacterium, EL-091S, was selected among phenol-degraders. The strain was identified with Pseudomows sp. from the result of taxonomical studies. The optimal condition for the biodegradation was as fellows: secondary carbon source, concentration of ammonium nitrate, temperature and pH were 200mg/l fructose, 600 mg/l, $30^{\circ}C$ and 7.0 respectively. The highest degradation rate of the 4-chlorophenol was about 58% for 24 hours incubation on the optimal condition. Biodegradation kinetics model of 5 mg/l 4-Chlorophenol, 10 mg/l 4-chlorophenol and 50 mg/l 4-chlorophenol were fitted the zero order kinetics model, respectively. Key Words : 4-chlorophenol, Pseudomonas sp., zero order kinetics model.

  • PDF

Biological Turf Restoration

  • Wilson, Carol W.;Kim, Hyung-Ki
    • Asian Journal of Turfgrass Science
    • /
    • v.7 no.1
    • /
    • pp.31-34
    • /
    • 1993
  • There is a growing concern in the United Stares over the environmental and human health implications associated with heavy use of water, pesticides, and inorganic ferilizers in maintaining picture perfect golf courses. There is also a growing awareness that a beautiful course is not necessarily a healthy course. The following discussion reviews the interrelationship of turfgrass and the soil that supports it and provides basic information on currently available alternatives to turf management practices that feature intensive application of inorganic fertilizers. water and pesticides. Soil is a dynamic natural environment in which microorganisms play an important role. Soil contains a large mass of microorganisms which produce thousands of enzymes that can catalyze the transformation and degradation of many organic molecules. (In top soil under optimum conditions may contain 10 billion cells per gram of soil.). Turfgrass and the soil which supports it are interdependent. The natural organic cycle as applied to turf and soil begins with healthy vigorous grass plants storing up the sun's energy in green plant tissues as chemical energy. Animals obtain energy by eating plants and when plants and animals die, their wastes are returned to the soil and provide "food" for soil microorganisms. In the next step of the organic cycle soil microorganisms break down complex plant tissues into more basic forms and make the nutrients available to grass roots. Finally, growing plants extract the available nutrients from the soil. By free operation of this organic cycle, natural grasslands have some of the most fertile soils on earths.

  • PDF

Preparation of Alginate/Chitosan Microcapsules and Enteric Coated Granules of Mistletoe Lectin

  • Lyu, Su-Yun;Kwon, Young-Ju;Joo, Hye-Jin;Park, Won-Bong
    • Archives of Pharmacal Research
    • /
    • v.27 no.1
    • /
    • pp.118-126
    • /
    • 2004
  • The aqueous extract of European mistletoe (Viscum album, L.) has been used in cancer therapy. The purified mistletoe lectins, main components of mistletoe, have demonstrated cytotoxic and immune-system-stimulating activities. Korean mistletoe (Viscum album L. coloratum), a subspecies of European mistletoe, has also been reported to possess anticancer and immunological activities. A galactose- and N-acetyl-D-galactosamine-specific lectin (Viscum album L. coloratum agglutinin, VCA) with Mr 60 kDa was isolated from Korean mistletoe. Mistletoe preparations have been given subcutaneously due to the low stability of lectin in the gastrointestinal (GI) tract. In the present study, we investigated the possibility of alginate/chitosan microcapsules as a tool for oral delivery of mistletoe lectin. In addition, our strategy has been to develop a system composed of stabilizing cores (granules), which contain mistletoe lectin, extract or powder, coated by a biodegradable polymer wall. Our results indicated that successful incorporation of VCA into alginate/chitosan microcapsules has been achieved and that the alginate/chitosan microcapsule protected the VCA from degradation at acidic pH values. And coating the VCA with polyacrylic polymers, Eudragit, produced outstanding results with ideal release profiles and only minimal losses of cytotoxicity after manufacturing step. The granules prepared with extract or whole plant produced the best results due to the stability in the extract or whole plant during manufacturing process.

Numerical analysis of the temperature distribution of the EM pump for the sodium thermo-hydraulic test loop of the GenIV PGSFR

  • Kwak, Jaesik;Kim, Hee Reyoung
    • Nuclear Engineering and Technology
    • /
    • v.53 no.5
    • /
    • pp.1429-1435
    • /
    • 2021
  • The temperature distribution of an electromagnetic pump was analyzed with a flow rate of 1380 L/min and a pressure of 4 bar designed for the sodium thermo-hydraulic test in the Sodium Test Loop for Safety Simulation and Assessment-Phase 1 (STELLA-1). The electromagnetic pump was used for the circulation of the liquid sodium coolant in the Intermediate Heat Transport System (IHTS) of the Prototype Gen-IV Sodium-cooled Fast Reactor (PGSFR) with an electric power of 150 MWe. The temperature distribution of the components of the electromagnetic pump was numerically analyzed to prevent functional degradation in the high temperature environment during pump operation. The heat transfer was numerically calculated using ANSYS Fluent for prediction of the temperature distribution in the excited coils, the electromagnet core, and the liquid sodium flow channel of the electromagnetic pump. The temperature distribution of operating electromagnetic pump was compared with cooling of natural and forced air circulation. The temperature in the coil, the core and the flow gap in the two conditions, natural circulation and forced circulation, were compared. The electromagnetic pump with cooling of forced circulation had better efficiency than natural circulation even considering consumption of the input power for the air blower. Accordingly, this study judged that forced cooling is good for both maintenance and efficiency of the electromagnetic pump.

Degradation of Microcystin-LR, Taste and Odor, and Natural Organic Matter by UV-LED Based Advanced Oxidation Processes in Synthetic and Natural Water Source (UV-LED기반 고도산화공정을 이용한 수중 마이크로시스틴-LR, 이취미 물질, 자연유기물 분해)

  • Yang, Boram;Park, Jeong-Ann;Nam, Hye-Lim;Jung, Sung-Mok;Choi, Jae-Woo;Park, Hee-Deung;Lee, Sang-Hyup
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.39 no.5
    • /
    • pp.246-254
    • /
    • 2017
  • Microcystin-LR (MC-LR) is one of most abundant microcystins, and is derived from blue-green algae bloom. Advanced oxidation processes (AOPs) are effective process when high concentrations of MC-LR are released into a drinking water treatment system from surface water. In particular, UV-based AOPs such as UV, $UV/H_2O_2$, $UV/O_3$ and $UV/TiO_2$ have been studied for the removal of MC-LR. In this study, UV-LED was applied for the degradation of MC-LR because UV lamps have demonstrated some weaknesses, such as frequent replacements; that generate mercury waste and high heat loss. Degradation efficiencies of the MC-LR (initial conc. = $100{\mu}g/L$) were 30% and 95.9% using LED-L (280 nm, $0.024mW/cm^2$) and LED-H (280 nm, $2.18mW/cm^2$), respectively. Aromatic compounds of natural organic matter changed to aliphatic compounds under the LED-H irradiation by LC-OCD analysis. For application to raw water, the Nak-dong River was sampled during summer when blue-green algae were heavy bloom in 2016. The concentration of extracellular and total MC-LR, geosmin and 2-MIB slightly decreased by increasing the LED-L irradiation; however, the removal of MC-LR by UV-LED (${\lambda}=280nm$) was insufficient. Thus, advanced UV-LED technology or the addition of oxidants with UV-LED is required to obtain better degradation efficiency of MC-LR.