Properites, of the Medium-Chain/Long-Chain Carnitine Acyltransferase Purified from Rat Liver Microsomes

Chung, Choong-Duk,Loran L. Bieber 제주대학교 1992 논문집 Vol.35 No.-

쥐 간의 마이크로소옴에서 분리한 medium-chain/long-chain carnitine acyltransferase의 몇가지 특성과 kinetic parameter들을 결정하였다. 이 효소는 carnitine octanoyltransferase라고 하며 탄소수가 6개에서 16개의 탄소사슬을 가지는 포화 지방산의 acyl-CoA류에 대한 반응에서 Ko??는 1.0에서 4.0μM의 값을 가졌으며, Vmax값은 이들에 대하여 조금 씩의 차이를 보였다. 이 효소는 정반응에서 반응 시간에 따라 일정비의 증가를 보였으나 역반응에서는 반응시간이 경과하면 증가비율이 더 커지는 경향을 나타내었다. 이러한 양상이 역반응을 조사하는데 대하여 어려움을 주었으나 Ko??는 decanoylcarnitine과 CoASH의 반응에서 보면, CoASH에 대하여는 0.3mM, decanoylcarnitine에 대하여는 1.0과 4.0mM사이에 있었다. 이 효소에 대한 kinetic data는 acylcarnitine을 합성하는 반응에 대한 효소의 기능을 말해준다. 그리고 이 효소는 aminocarnitine에 의하여 어느 정도 저해가 되며 D-carnitine의 저해작용은 약했다. 이 효소를 기질의 없는 상태에서 4.4'dipyridildisulfide(-SH modifier 일종)과 항온처리반응을 시킨 후에는 활성이 저해되었다. 이러한 억제 작용은 여러가지 acyl-CoA들과 carnitine이 존재하에서는 일어나지 않았다. 다른 실험 결과들이 보여주는 것처럼 valproylcarnitine, 3-methylglutarylcanrnitine 또는 pivaloylcarnitine을 기질로 한 경우에는 조금 사용하거나 사용하지 못하였다. 막에 존재하는 다른 효소들의 연구결과와 비교하면 이 효소는 malonyl-CoA에 의해서 저해 받지 않았으나 etomoxiryl-CoA는 약간 저해시키는 효과를 나타내었다. COT에 대한 polyclonal antibody를 얻어서 순수 분리된 효소에 대한 Western blot을 한 결과 마이크로소옴의 단백질에 대한 COT의 M.W.는 53,000dalton이었다. anti-microsomal COT antibody는 순수 분리된 쥐 심장의 미토콘드리아의 carnitine palmitoyltransferase와 peroxisome의 COT에 대하여 약한 cross 반응을 보였으나 carnitine acetyltransferase와는 cross 반응을 하지 않았다. anti-mitochondrial CPT와 anti-peroxsomal CAT에 대한 microsomal COT는 cross반응을 보이지 않았다. 억제제에 대한 실험 data와 분자량 Western blot분석결과는 쥐 간의 마이크로소옴에서 정제된 효소에 대한 결과이나 다른 세포 소기관에서 분리한 carnitine acyltransferase는 이전에 정제된 효소를 사용하였다.

High concentrations of single-walled carbon nanotubes lower soil enzyme activity and microbial biomass

Jin, L.,Son, Y.,Yoon, T.K.,Kang, Y.J.,Kim, W.,Chung, H. Academic Press 2013 Ecotoxicology and environmental safety Vol.88 No.-

Nanomaterials such as single-walled carbon nanotubes (SWCNTs) may enter the soil environment with unknown consequences resulting from the development of nanotechnology for a variety of applications. We determined the effects of SWCNTs on soil enzyme activity and microbial biomass through a 3-week incubation of urban soils treated with different concentrations of SWCNTs ranging from 0 to 1000μgg<SUP>-1</SUP> soil. The activities of cellobiohydrolase, β-1,4-glucosidase, β-1,4-xylosidase, β-1,4-N-acetylglucosaminidase, l-leucine aminopeptidase, and acid phosphatase and microbial biomass were measured in soils treated with powder and suspended forms of SWCNTs. SWCNTs of concentrations at 300-1000μgg<SUP>-1</SUP> soil significantly lowered activities of most enzymes and microbial biomass. It is noteworthy that the SWCNTs showed similar effects to that of multi-walled carbon nanotubes (MWCNTs), but at a concentration approximately 5 times lower; we suggest that this is mainly due to the higher surface area of SWCNTs than that of MWCNTs. Indeed, our results show that surface area of CNTs has significant negative relationship with relative enzyme activity and biomass, which suggests that greater microorganism-CNT interactions could increase the negative effect of CNTs on microorganisms. Current work may contribute to the preparation of a regulatory guideline for the release of CNTs to the soil environment.

Simulation of Rough Rice Drying by Natural Air(Ⅰ)

Chang, D. I.,Chung, D. S.,Pfost, H. B.,Calderwood, D. L. 충남대학교 농업과학연구소 1983 農業技術硏究報告 Vol.10 No.1

Simulation model of natural air grain drying was discussed and modified to predict the changes of grain moisture content and dry matter loss of rough rice drying. The modified simulation model was then validated using actual test data. A series of simulated drying tests using official weather data for 15 years from Beaumont, Texas, was taken to make minimum airflow rate and maximum bed depth of rough rice drying by natural air, under different conditions of initial moisture content of rough rice, airflow rate and harvest date.

Inactivation of foodborne pathogens in powdered red pepper (Capsicum annuum L.) using combined UV-C irradiation and mild heat treatment

Cheon, H.L.,Shin, J.Y.,Park, K.H.,Chung, M.S.,Kang, D.H. Butterworths ; Taylor Francis ; Elsevier Science 2015 Food Control Vol.50 No.-

This study was performed to investigate the effectiveness of combined ultraviolet (UV-C) irradiation and mild heating as an alternative to conventional inactivation of foodborne pathogens, including Escherichia coli O157:H7 and Salmonella Typhimurium on powdered red pepper. A cocktail of three strains of E. coli O157:H7 ATCC 35150, ATCC 43889, ATCC 43890) and S. Typhimurium (ATCC 19585, ATCC 43971, DT 104) was inoculated onto powdered red pepper and then treated with UV-C irradiation and mild heat. A constant UV intensity (3.40 mW/cm<SUP>2</SUP>) of the emitting lamps was applied to samples for 5, and 10 min at 25, 35, 45, 55, and 65 <SUP>o</SUP>C, respectively. Also, quality change of powdered red pepper was measured in order to identify the efficiency of combined treatment. The reduction levels of E. coli O157:H7 and S. Typhimurium on powdered red pepper when treated with UV-C irradiation alone at 20.4 kJ/m<SUP>2</SUP> for 10 min was 0.22 and 0.29 log CFU/g, respectively. While, combined treatment with mild heating at 65 <SUP>o</SUP>C reduced the surviving numbers of each pathogens by 2.88 and 3.06 log CFU/g, respectively. Although the inactivation efficiency was influenced less by the UV-C radiation dose, the synergistic effect was observed with increasing temperature and UV-C radiation dose. CIE color value and extractable color value were not significantly (P > 0.05) different between non-treated and combination treated samples. The moisture and capsaicinoids contents showed significant (P < 0.05) differences when treated at 65 <SUP>o</SUP>C because of sample drying during heat treatment. Therefore, these results suggest that UV-C irradiation combined with mild heating can be utilized by the food industry in order to effectively inactivate E. coli O157:H7 and S. Typhimurium without incurring quality deterioration of powdered red pepper.

Evaluation of the taxonomic rank of the terrestrial orchid Cephalanthera subaphylla based on allozymes

Mi Yoon Chung,Sung-Won Son,정재민,Jordi LÓPEZ-PUJOL,Tomohisa Yukawa,정명기 한국식물분류학회 2019 식물 분류학회지 Vol.49 No.2

The taxonomic rank of the tiny-leaved terrestrial orchid Cephalanthera subaphylla Miyabe & Kudô has been somewhat controversial, as it has been treated as a species or as an infraspecific taxon, under C. erecta (Thunb.) Blume [C. erecta var. subaphylla (Miyabe & Kudô) Ohwi and C. erecta f. subaphylla (Miyabe & Kudô) M. Hiro]. Allozyme markers, traditionally employed for delimiting species boundaries, are used here to gain information for determining the taxonomic status of C. subaphylla. To do this, we sampled three populations of five taxa (a total of 15 populations) of Cephalanthera native to the Korean Peninsula [C. erecta, C. falcata (Thunb.) Blume, C. longibracteata Blume, C. longifolia (L.) Fritsch, and C. subaphylla]. Among 20 putative loci resolved, three were monomorphic (Dia-2, Pgi-1, and Tpi-1) across the five species. Apart from C. longibracteata, there was no allozyme variation within the remaining four species. Of the 51 alleles harbored by these 17 polymorphic loci, each of the 27 alleles at 14 loci was unique to a single species. Accordingly, we found low average values of Nei’s genetic identities (I) between ten species pairs (from I = 0.250 for C. erecta versus C. longifolia to I = 0.603 for C. falcata vs. C. longibracteata), with C. subaphylla being genetically clearly differentiated from the other species (from I = 0.349 for C. subaphylla vs. C. longifolia to 0.400 for C. subaphylla vs. C. falcata). These results clearly indicate that C. subaphylla is not genetically related to any of the other taxa of Cephalanthera that are native to the Korean Peninsula, including C. erecta. In a principal coordinate analysis (PCoA), C. subaphylla was positioned distant not only from C. falcata, C. longibracteata, and C. longifolia, but also from C. erecta. Finally, K = 5 was the best clustering scheme using a Bayesian approach, with five clusters precisely corresponding to the five taxa. Thus, our allozyme results strongly suggest that C. subaphylla merits the rank of species.

Optimization of chitosanase production from Bacillus sp. RKY3 using statistical experimental designs

Wee, Young-Jung,Reddy, L. V. A.,Chung, Ki-Chul,Ryu, Hwa-Won John Wiley Sons, Ltd. 2009 Journal of chemical technology and biotechnology Vol.84 No.9

<P>BACKGROUND: The culture medium and fermentation conditions for the production of constitutive chitosanase from a newly isolated Bacillus sp. RKY3 were optimized statistically.</P><P>RESULTS: The variables significantly influencing both chitosanase production and cell growth were screened through the Plackett–Burman design, by which maltose, beef extract, MgSO<SUB>4</SUB>, and incubation time were identified as the most significant variables. The optimum values of the selected variables and their mutual interactions were determined through the steepest ascent method and Box–Behnken experimental design. The results demonstrated that 62.30 U mL<SUP>−1</SUP> chitosanase activity was predicted with optimum conditions of maltose (30.18 g L<SUP>−1</SUP>), beef extract (15.25 g L<SUP>−1</SUP>), MgSO<SUB>4</SUB> (0.26 g L<SUP>−1</SUP>), and incubation time (50.02 h). The predicted response was verified by the validation experiments, and the optimum conditions resulted in a maximum chitosanase activity of 63.53 ± 1.22 U mL<SUP>−1</SUP>.</P><P>CONCLUSION: The optimization of fermentation variables resulted in an approximately 11.3-fold increase in chitosanase activity compared with that observed under unoptimized conditions (from 5.63 U mL<SUP>−1</SUP> to 63.53 U mL<SUP>−1</SUP>). Copyright © 2009 Society of Chemical Industry</P>

Topiramate stimulates glucose transport through AMP-activated protein kinase-mediated pathway in L6 skeletal muscle cells

Ha, E,Yim, S V,Jung, K H,Yoon, S H,Zheng, L T,Kim, M J,Hong, S J,Choe, B K,Baik, H H,Chung, J H,Kim, J W Nature Publishing Group 2006 The pharmacogenomics journal Vol.6 No.5

The use of topiramate (TPM) in the treatment of binge-eating disorder, bulimia nervosa, and antipsychotic-induced weight gain has recently increased, however, the exact molecular basis for its effects on body weight reduction and improved glucose homeostasis, is yet to be elucidated. Here we investigated the effect and signaling pathway of TPM on glucose uptake in L6 rat skeletal muscle cells, which account for >70% of glucose disposal in the body. Intriguingly, we found that TPM (10 μM) stimulated the rate of glucose uptake up to twofold increase. And TPM-stimulated glucose transport was inhibited with the overexpression of dominant-negative form of AMP-activated protein kinase (AMPK), an important mediator in glucose transport, implicating that AMPK-mediated pathway is involved. The TPM-stimulated glucose transport was blocked by SB203580, a specific inhibitor of AMPK downstream mediator, p38 mitogen-activated protein kinase (MAPK) protein. LY294002, an inhibitor of phosphatidylinositol (PI) 3-kinase, which is another crucial mediator in independent glucose transport pathway, did not inhibit TPM-stimulated glucose transport. We also found that TPM increased the phosphorylation level of AMPK and p38 MAPK, whereas no effect on the activity of PI 3-kinase of TPM, when assessed by PI 3-kinase assay, was observed. These results together suggest that TPM stimulates glucose transport, not via PI 3-kinase mediated, but via AMPK-mediated pathway in skeletal muscle cells, thereby contributing to the body weight regulation and glucose homeostasis.The Pharmacogenomics Journal (2006) 6, 327–332. doi:10.1038/sj.tpj.6500366; published online 17 January 2006

Equilibrium and global MHD stability study of KSTAR high beta plasmas under passive and active mode control

Katsuro-Hopkins, O.,Sabbagh, S.A.,Bialek, J.M.,Park, H.K.,Bak, J.G.,Chung, J.,Hahn, S.H.,Kim, J.Y.,Kwon, M.,Lee, S.G.,Yoon, S.W.,You, K.-I.,Glasser, A.H.,Lao, L.L. International Atomic Energy Agency 2010 Nuclear fusion Vol.50 No.2

<P>The Korea Superconducting Tokamak Advanced Research, KSTAR, is designed to operate a steady-state, high beta plasma while retaining global magnetohydrodynamic (MHD) stability to establish the scientific and technological basis of an economically attractive fusion reactor. An equilibrium model is established for stability analysis of KSTAR. Reconstructions were performed for the experimental start-up scenario and experimental first plasma operation using the EFIT code. The VALEN code was used to determine the vacuum vessel current distribution. Theoretical high beta equilibria spanning the expected operational range are computed for various profiles including generic L-mode and DIII-D experimental H-mode pressure profiles. Ideal MHD stability calculations of toroidal mode number of unity using the DCON code shows a factor of 2 improvement in the wall-stabilized plasma beta limit at moderate to low plasma internal inductance. The planned stabilization system in KSTAR comprises passive stabilizing plates and actively cooled in-vessel control coils (IVCCs) designed for non-axisymmetric field error correction and stabilization of slow timescale MHD modes including resistive wall modes (RWMs). VALEN analysis using standard proportional gain shows that active stabilization near the ideal wall limit can be reached with feedback using the midplane segment of the IVCC. The RMS power required for control using both white noise and noise taken from NSTX active stabilization experiments is computed for beta near the ideal wall limit. Advanced state-space control algorithms yield a factor of 2 power reduction assuming white noise while remaining robust with respect to variations in plasma beta.</P>

1997~2000년에 발생된 황사에 관한 연구

정용승,김학성,낫짜가도르지 엘,적데어 디,첸 수잰 한국교원대학교 환경과학연구소 2002 환경연구논문집 Vol.- No.7

Joint monitoring of yellow sand (YS) phenomena occurred from 1997 to 2000 was carried out. It was found that the YS in source regions occurred in any time during the year, while the severe dust storms occurred frequently from March to May after the spring thaw. Wind erosion occurred usually with wind greater than about 8 ms^-1 in the source region in any seasons. However, severe YS phenomenon found to occur with wind greater than 15 ms^-1 at least for 3 hours or more. In source regions, YS occurred over 60∼120 days per year. In Korea, YS was found to occur 8∼12 cases per year with 12-22 YS days. It was recorded that maximum concentrations of TSP were 989∼1396 ㎍ m^-3 with PM10 values of 861∼996 ㎍ m^-3 and with the lowest visibility of 1.4∼1.6km. In Mongolia, however, it was observed that the number of dusty days decreased due to the increase in rainy days.

아시아 12개국의 응급의학 실태에 대한 연구 조사

정제명,왕순주,안무업,박재형,유기철,박준석,강재구,제프리 아놀드 대한응급의학회 1999 대한응급의학회지 Vol.10 No.4

Background : To assess the current level of development of emergency medicine (EM) systems in Asia. Method : Survey of EM professionals from 12 Asian countries during a 90-day period from August to November 1998. 12 EM professionals from 12 Asian countries completed the survey. All participants were physicians. 7 participants (58%) gave presentations at an international EM conference during the study period. Respondents completed a 103 question questionnaire about the status of EM specialty, academic, patient care, information and management systems and the factors influencing the future of EM in their countries. Results : 92% of respondents stated that their countries have hospital-based emergency departments (ED). More than 80% of respondents reported that their countries have EMS systems and ED systems for trauma care and patient transfer. More than 70% stated that their countries have national EM organizations, EM research, national EMS activation phone numbers, ED systems for pediatric emergency care, emergency physician (EP) training in ACLS and ATLS and peer review. More than 60% reported official recognition of EM as an independent specialty status, ED triage systems and systems for customer service. More than 50% reported EM residency training programs, EM journals and EP ability to perform rapid sequence intubation (RSI). 50% reported EP ability to perform thrombolysis for acute MI and 33% reported EP ultrasonography. 92% felt that a lack of funding posed a moderate or great obstacle to the future development of EM in their countries. Conclusions : Many essential systems of EM now exist throughout Asia. In the systems of administration and emergency medical information in many countries, there are some parts to be developed further.