• Title/Summary/Keyword: cleavage.

Search Result 2,074, Processing Time 0.023 seconds

페놀 분해 Rhodococcus sp. DGUM 2011의 분리 및 특성

  • 오정석;한영환
    • Microbiology and Biotechnology Letters
    • /
    • v.25 no.5
    • /
    • pp.459-463
    • /
    • 1997
  • A bacterium DGUM 2011 has been selected from various samples of industrial wastewater and soil. Based on the morphological and physiological characteristics, the isolate DGUM 2011 was identified as Rhodococcus sp. and named as Rhodococcus sp. DGUM 2011. The optimal temperature and pH for the cell growth of Rhodococcus sp. DGUM 2011 were 37$\circ$C and 7.6, respectively. When phenol was added to the minimal media as a sole source of carbon and energy, the concentrations of maximum and optimum for cell growth was 0.10% and 0.08%, respectively. When 0.05% phenol was given in the minimal media, Rhodococcus sp. DGUM 2011 completely utilize it within 24 hrs. The isolate could utilize benzoic acid, p-hydroxybenzoate, p-cresol, tyrosine and phloroglucinol. The isolate possessed both catechol 1,2-dioxygenase and 2,3-dioxygenase activity. However, the activity of catechol 1,2-dioxygenase was much higher than that of 2,3-dioxygenase, which suggests that the isolate might degrade phenol via both ortho- and meta-cleavage, mainly via ortho-cleavage.

  • PDF

Strength Evaluation for Adhesive Bonds of Adhesive with FRP Ship Body Structure (FRP 선체구조용 접착제의 접착강도 평가)

  • Ahn, Seok-Hwan;Choi, Han-Kyu;Nam, Ki-Woo
    • Journal of Ocean Engineering and Technology
    • /
    • v.24 no.1
    • /
    • pp.146-152
    • /
    • 2010
  • Recently, the applied frequency of composite materials was increased from the viewpoint of lightweight, high strength and low cost when a leisure boat and a fishing boatwere built. However, studies on the mechanical properties of composite material with ship are rare. Specially, a leisure boat and fishing boat with FRP had been built by hand lay-up method. However, the vacuum infusion method is rising recently for ship building. The manufactured these FRP plates were combined by using the adhesive. Therefore, in this study Cleavage peel strength, Shear strength and fatigue limit of adhesive bonds by tensileloading were estimated. From test results, the strengths of FRP specimens made by the vacuum infusion method are higher than that of the hand lay-up method.

Imperfections in $LiTaO_3$ Crystal ($LiTaO_3$ 단결정의 결함)

  • 김한균;박승익;박현민;정수진
    • Journal of the Korean Ceramic Society
    • /
    • v.31 no.2
    • /
    • pp.147-154
    • /
    • 1994
  • The imperfections of LiTaO3 crystals grown from the Pt-Rh and the Ir crucible were investigated with X-ray diffraction, optical and electron microscope. The growth direction was <100>h and the plane parallel to the plane connecting two main growth ridges was (012)h which would be the main cleavage plane. The dislocation density in the specimen cut parallel to (012)h plane increased with polishing time and the inverted ferroelectric microdomains were induced based on this dislocations. Such imperfections as 180$^{\circ}$ domains, microcracks, dislocations and stacking faults. could be found in the LiTaO3 crytals. The crystal contaminated with lots of Rh form Pt-Rh crucible during the crystal growing under air atmosphere contained more imperfections. The main cleavage plane and subgrain boundary parallel to its growing axis might be the main source of reducing the mechnical strength during the wafering process.

  • PDF

Thermal Dissociation and Conformational Lock of Superoxide Dismutase

  • Hong, J.;Moosavi-Movahedi, A.A.;Ghourchian, H.;Amani, M.;Amanlou, M.;Chilaka, F.C.
    • BMB Reports
    • /
    • v.38 no.5
    • /
    • pp.533-538
    • /
    • 2005
  • The kinetics of thermal dissociation of superoxide dismutase (SOD) was studied in 0.05 M Tris-HCl buffer at pH 7.4 containing $10^{-4}\;M$ EDTA. The number of conformational locks and contact areas and amino acid residues of dimers of SOD were obtained by kinetic analysis and biochemical calculation. The cleavage bonds between dimers of SOD during thermal dissociation and type of interactions between specific amino acid residues were also simulated. Two identical contact areas between two subunits were identified. Cleavage of these contact areas resulted in dissociation of the subunits, with destruction of the active centers, and thus, lost of activity. It is suggested that the contact areas interact with active centers by conformational changes involving secondary structural elements.

Mouse Embryo Culture as Quality Control for Human In Vitro Fertilization (생쥐 체외수정 정도관리의 유용성에 관한 실험적 연구)

  • Lim, Young-Kyung;Park, Hyun-Jeong;Lee, Yu-Il
    • Clinical and Experimental Reproductive Medicine
    • /
    • v.18 no.1
    • /
    • pp.49-53
    • /
    • 1991
  • The development of 2-cell mouse embryos to the blastocyst stage in vitro has been used as a quality control for the media empolyed for human in vitro fertilization. There was a comparison between the quality control data of the culture medium as ascertained by 2-cell mouse embryos development and sperm motility and the data from fertilization and cleavage of human oocytes. However, there was no obvious association between fertilization and cleavage of human oocytes and the quality of the medium ascertained by mouse embryo development and sperm motility.

  • PDF

Synthesis of Benzophenanthridine-Related Alkaloids (벤조펜안드리딘과 관련된 알칼로이드의 합성)

  • Kim, Sin-Kyu;Lee, Hyung-Won;Kim, In-Jong;Lee, Ma-Se
    • YAKHAK HOEJI
    • /
    • v.36 no.3
    • /
    • pp.250-254
    • /
    • 1992
  • Benzo[C]phenanthidine alkaloids were found to exhibit considerably strong antileukemic activies. These alkaloids have been shown to be biosynthesized from the corresponding alkaloids throung an oxidative $C_6-N$ bond cleavage followed by recyclization between $C_6\;and\;C_{13}$ position of the protoberberine. Recently we have achieved the biomimetic transformation of protoberberine alkaloid, berberine into benzo[C]phenanthridine alkaloid, chelerythrine.

  • PDF

Characterization of Tetracycline Resistant Plasmid in Staphylococcus aureus by Restriction Enzyme Mapping (황색포도상구균에서 테트라사이클린 내성을 나타내는 플라스미드의 동정)

  • Kim, Ki-Hyun;Kim, Jong-Myung;Moon, Kyung-Ho
    • YAKHAK HOEJI
    • /
    • v.36 no.3
    • /
    • pp.255-258
    • /
    • 1992
  • The clinical isolate Staphylococcus aureus SA8 was resistant to tetracycline(Tc) and harboured a plasmid pKH1(24.82 kb). pKH1 was shown by curing and by transformation to specify resistance to Tc. The cleavage map of a pKH1 was determined by restricction enzyme mapping techniques. Cleavage map is given for BglII, EcoRI, HpaII, PvuII and SalI. Restriction endonuclease BamHI, BglI, BstEII, HpaI, PstI, and XhoI have no sites on this plasmid. HaeIII, XbaI, and HindIII have 5, 6, 14 sites, respectively.

  • PDF

Simple Purification of Escherichia coli-Derived Recombinant Human Interleukin-2 Expressed with N-terminus Fusion of Glucagon

  • Won Hye-Soon;Lee Jeewon;Kim In-Ho;Park Young-Hoon
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • v.5 no.1
    • /
    • pp.13-16
    • /
    • 2000
  • Simple procedures have been devised for purifying recombinant human interleukin-2 (hIL-2), which was expressed in Escberichia coli using sequences of glucagon molecules and enterokinase cleavage site as an N-terminus fusion partner. The insoluble aggregates of recombinant fusion protein produced in E. coli cytoplasm were easily dissolved by simple alkaline pH shift $(8\rightarrow12\rightarrow8)$. Following enterokinase cleavage, the recombinant hIL-2 was finally purified by one-step reversed-phase HPLC with high purity. The ease and high efficiency of this simple purification process seem to mainly result from the role of used glucagon fusion partner, which could be applied to the production of other therapeutically important proteins.

  • PDF

Effects of Neutral, Cationic, and Anionic Chromium Ascorbate Complexes on Isolated Human Mitochondrial and Genomic DNA

  • Ay, Ahmet Nedim;Zumreoglu-Karan, Birgul;Oner, Reyhan;Unaleroglu, Canan;Oner, Cihan
    • BMB Reports
    • /
    • v.36 no.4
    • /
    • pp.403-408
    • /
    • 2003
  • The relative activities of neutral, cationic, and anionic chromium ascorbate complexes toward isolated human mitochondrial and genomic DNA were investigated at physiologically relevant conditions by agarose gel electrophoresis. A direct relationship between the charge of the Cr(III) species and their DNA-damaging properties was found. The cationic species were found to be fully capable of DNA-cleavage, even in short incubation periods. Incubations were also performed in the presence of amino acids. No apparent effect was observed under the applied experimental conditions to facilitate or prevent damage through the ternary amino acid-Cr-DNA adduct formation or binary chromium-amino acid complex formation.

Constraint Loss Assessment of SA508 PCVN Specimen according to Crack depth (SA508 PCVN 시편의 균열깊이에 따른 구속력 손실 평가)

  • Park, Sang-Yun;Lee, Ho-Jin;Lee, Bong-Sang
    • Proceedings of the KSME Conference
    • /
    • 2008.11a
    • /
    • pp.161-166
    • /
    • 2008
  • In general structures, cleavage fracture may develop under the low constraint condition of larger scale yielding with a shallow surface crack. However, standard procedures for fracture toughness testing require very severe restrictions of specimen geometry. So the standard fracture toughness data makes the integrity assessment irrationally conservative. In this paper, cleavage fracture toughness tests have been made on side-grooved PCVN (precracked charpy V-notch) type specimens (10 by 10 by 55 mm) with varying crack depth, The constraint effects on the crack depth ratios are quantitatively evaluated by scaling model and Weibull stress method using 3-D finite clement method, After correction of constraint loss due to shallow crack depths, the statistical size effect are also corrected according to the standard ASTM E 1921 procedure, The results snowed a good agreement in the geometry correction regardless of the crack size, while some over-corrections were observed in the corrected values of $T_0$.

  • PDF