Substrate specificity of a recombinant d-lyxose isomerase from Providencia stuartii for monosaccharides

Kwon, H.J.,Yeom, S.J.,Park, C.S.,Oh, D.K. Society for Bioscience and Bioengineering, Japan ; 2010 Journal of bioscience and bioengineering Vol.110 No.1

The specific activity and catalytic efficiency (k<SUB>cat</SUB>/K<SUB>m</SUB>) of the recombinant putative protein from Providencia stuartii was the highest for d-lyxose among the aldose substrates, indicating that it is a d-lyxose isomerase. Gel filtration analysis suggested that the native enzyme is a dimer with a molecular mass of 44 kDa. The maximal activity for d-lyxose isomerization was observed at pH 7.5 and 45 <SUP>o</SUP>C in the presence of 1 mM Mn<SUP>2+</SUP>. The enzyme exhibited high isomerization activity for aldose substrates with the C2 and C3 hydroxyl groups in the left-hand configuration, such as d-lyxose, d-mannose, l-ribose, d-talose, and l-allose (listed in decreasing order of activity). The enzyme exhibited the highest activity for d-xylulose among all pentoses and hexoses. Thus, d-lyxose was produced at 288 g/l from 500 g/l d-xylulose by d-lyxose isomerase at pH 7.5 and 45 <SUP>o</SUP>C for 2 h, with a conversion yield of 58 % and a volumetric productivity of 144 g l<SUP>-1</SUP> h<SUP>-1</SUP>. The observed k<SUB>cat</SUB>/K<SUB>m</SUB> (920 mM<SUP>-1</SUP> s<SUP>-1</SUP>) of P. stuartiid-lyxose isomerase for d-xylulose is higher than any of the k<SUB>cat</SUB>/K<SUB>m</SUB> values previously reported for sugar and sugar phosphate isomerases with monosaccharide substrates. These results suggest that the enzyme will be useful as an industrial producer of d-lyxose.

Study of Cryogenic Conduction Cooling Systems for an HTS SMES

Yeom, H.K.,Hong, Y.J.,Park, S.J.,Seo, T.B.,Seong, K.C.,Kim, H.J. IEEE 2007 IEEE transactions on applied superconductivity Vol.17 No.2

<P>Superconducting magnetic energy storage (SMES) is more fast response, economical, and environment-friendly than uninterruptible power supply (UPS) using the battery. And the SMES not only has the ability to control active and reactive power simultaneously, but also has a long life time because the superconducting magnet does not have degradation problem which the battery has. Therefore, the SMES is a candidate for instead of the UPS using the battery. The SMES needs cryogenic system without exception. A conduction cooling system that has a simple, light and small structure is well adapted to high temperature superconducting (HTS) SMES. The cryogenic conduction cooling system is needed some technologies such as insulation, vacuum, and thermal analysis. Conduction heat is mainly transferred by cooler port, access port, support bar, etc., and radiation heat is transferred by vacuum chamber, thermal shield and HTS coil surface. The heat loads through the conduction and radiation of cryostat are calculated. Radiation shield heat load, temperature of HTS coil and conduction copper plate are estimated and measured. A cryopumping effect of cooled radiation shield was observed. A current lead and HTS coil heat load was evaluated to maintain HTS coil temperature was under 20 K.</P>

Global Warming Gas Emission during Plasma Cleaning Process of Silicon Nitride Using c-C₄F₈O Feed Gas with Additive N₂

K. J. Kim,C. H. Oh,N.-E. Lee,J. H. Kim,J. W. Bae,G. Y. Yeom,S. S. Yoon 한국표면공학회 2001 한국표면공학회지 Vol.34 No.5

5-Bromo-2--deoxyuridine induced effluvium via p53-mediated CD326-positive keratinocyte apoptosis in C57BL/6 mice

Uh, K. J.,Hwang, W. S.,Bae, J. H.,Jang, D. E.,Yeom, S. C. Blackwell Publishing Ltd 2017 The Journal of Dermatology Vol.44 No.2

<P>Anagen effluvium develops because of disturbances in the hair follicle cycle, leading to acute and severe hair loss in humans. The objective of this study was to establish a mouse model of anagen effluvium by 5-bromo-2-deoxyuridine (BrdU) treatment, and evaluate the pathological changes and underlying mechanisms. We treated 9-10-day-old pups and 3-7-week-old C57BL/6 mice with BrdU. After successfully inducing hair loss in the neonatal pups, microscopic, immunohistochemical and flow cytometry analyses were conducted. BrdU induced early onset alopecia in neonates and caused epidermal thickening and hair shaft breakage. BrdU appeared to incorporate the CD326-positive keratinocyte layer and induced p53-related apoptosis. Keratinocyte apoptosis caused immune cell infiltration in the dermal region; M2 macrophages and neutrophils were dominant. The BrdU-induced hair loss was dose-dependent, and alopecia was visible at a dose range of 25-200 g/g bodyweight. The BrdU-induced anagen effluvium mouse model is novel and easily established by administrating four simple BrdU injections to pups; these mice showed synchronized onset of alopecia symptoms with little individual variation. Moreover, this model showed an alopecia phenotype similar to that of human anagen effluvium with acute, severe and widespread hair loss.</P>

Substrate specificity of a recombinant <small>D</small>-lyxose isomerase from <i>Serratia proteamaculans</i> that produces <small>D</small>-lyxose and <small>D</small>-mannose

Park, C.-S.,Yeom, S.-J.,Lim, Y.-R.,Kim, Y.-S.,Oh, D.-K. Blackwell Publishing Ltd 2010 Letters in applied microbiology Vol.51 No.3

<P>Abstract</P><P>Aims: </P><P>Characterization of substrate specificity of a <SMALL>D</SMALL>-lyxose isomerase from <I>Serratia proteamaculans</I> and application of the enzyme in the production of <SMALL>D</SMALL>-lyxose and <SMALL>D</SMALL>-mannose.</P><P>Methods and Results: </P><P>The concentrations of monosaccharides were determined using a Bio-LC system. The activity of the recombinant protein from <I>Ser. proteamaculans</I> was the highest for <SMALL>D</SMALL>-lyxose among aldoses, indicating that it is a <SMALL>D-</SMALL>lyxose isomerase. The native recombinant enzyme existed as a 54-kDa dimer, and the maximal activity for <SMALL>D-</SMALL>lyxose isomerization was observed at pH 7·5 and 40°C in the presence of 1 mmol l<SUP>−1</SUP> Mn<SUP>2+</SUP>. The <I>K</I><SUB>m</SUB> values for <SMALL>D</SMALL>-lyxose, <SMALL>D</SMALL>-mannose, <SMALL>D</SMALL>-xylulose, and <SMALL>D</SMALL>-fructose were 13·3, 32·2, 3·83, and 19·4 mmol l<SUP>−1</SUP>, respectively. In 2 ml of reaction volume at pH 7·5 and 35°C, <SMALL>D</SMALL>-lyxose was produced at 35% (w/v) from 50% (w/v) <SMALL>D</SMALL>-xylulose by the <SMALL>D-</SMALL>lyxose isomerase in 3 h, while <SMALL>D</SMALL>-mannose were produced at 10% (w/v) from 50% (w/v) <SMALL>D</SMALL>-fructose in 5 h.</P><P>Conclusions: </P><P>We identified the putative sugar isomerase from <I>Ser. proteamaculans</I> as a <SMALL>D</SMALL>-lyxose isomerase. The enzyme exhibited isomerization activity for aldose substrates with the C2 and C3 hydroxyl groups in the left-hand configuration. High production rates of <SMALL>D-</SMALL>lyxose and <SMALL>D</SMALL>-mannose by the enzyme were obtained.</P><P>Significance and Impact of the Study: </P><P>A new <SMALL>D-</SMALL>lyxose isomerase was found, and this enzyme had higher activity for <SMALL>D</SMALL>-lyxose and <SMALL>D</SMALL>-mannose than previously reported enzymes. Thus, the enzyme can be applied in industrial production of <SMALL>D</SMALL>-lyxose and <SMALL>D</SMALL>-mannose.</P>

Effect of pulse phase lag in the dual synchronized pulsed capacitive coupled plasma on the etch characteristics of SiO₂ by using a C₄F₈/Ar/O₂ gas mixture

Jeon, M.H.,Yang, K.C.,Kim, K.N.,Yeom, G.Y. Pergamon Press [etc.] 2015 Vacuum Vol.121 No.-

The characteristics of a synchronized pulse plasma using 60 MHz radio frequency as a source power and 2 MHz radio frequency as a bias power were investigated for the etching of SiO<SUB>2</SUB> masked with an amorphous carbon layer (ACL) in a C<SUB>4</SUB>F<SUB>8</SUB>/Ar/O<SUB>2</SUB> gas mixture. Especially, the effects of the pulse phase lag of the synchronized dual-frequency pulsing between source power and bias power on the characteristics of the plasma and SiO<SUB>2</SUB> etching were investigated. The results showed that the etch rates of SiO<SUB>2</SUB> was the highest and the etch profile was the most anisotropic when the pulse phase lag between the source power and bias power was 0<SUP>o</SUP> in the synchronized pulse plasma. Increasing the phase lag to 180<SUP>o</SUP> decreased the etch rates and degraded the etch anisotropy. The change in etch characteristics as a function of pulse phase lag was believed to be related to the difference in gas dissociation and fluorocarbon passivation caused by the variations in electron temperatures during the source pulse off-time.

Molecular Composition and Fractionation of Colostral Casein with Advancing Lactation

Han, K. S 韓國酪農學會 1997 韓國酪農學會誌 Vol.19 No.1

Fractionation of bovine x-Casein

Kang, S. H 韓國酪農學會 1996 韓國酪農學會誌 Vol.18 No.3

制酸劑에 關한 硏究 : 沈澱 pH의 影響 Effect of pH on the precipitation of aluminum hydroxide

鄭三逵,李啓胄,金榮培,李吉哲,張聖宰,廉潤姬 國立保健硏究院 1975 국립보건연구원보 Vol.12 No.-

Acridine Orange 염색법을 이용한 말라리아의 진단

임채승,김영기,이갑노,김대성,김순덕,염용태 대한감염학회 1997 감염 Vol.29 No.2

배경:최근 한국에서의 토착형 말라리아는 1993년을 기점으로 점차 증가하여 1996년도에는 발생 환자가 350명을 넘게 되어 한국도 이제 토착형 말라리아가 정착한 것으로 추정된다. 그러나 아직까지 말라리아의 진단은 말초혈액도말이나 후층도말법등 기초적인 진단법에 의존하고 있어 예민도가 높은 진단법이 요구되는 상황이나 아직 국내의 연구는 부족하여 저자들은 말라리아 진단시 예민도가 높다고 보고된 형광 염색법인 acridine orange염색법을 적용하여 기존의 진단법과 비교하였다. 방법:저자들은 1996년 경기도에서 의뢰된 말라리아 의심 검체 20개와 군 병원에 입원한 환자 67명의 치료전 후 혈액을 이용하여 박충 및 후충도말을 만들어 Giemsa 염색을 실시하였고 동일 혈액도말검체에 acridine orange 염색액을 한 방울(10-50㎍/mL)떨어뜨려 염색을 실시하였다. 이를 경험이 풍부한 말라리아 전문가가 광학 현미경과 형광 현미경으로 판독하여 각 방법간의 예민도를 비교하였다. 결과:대상 검체에서 acridine orange 염색법의 예민도는 83%로 박충도말법과(82%) 후충도말법(83%)과 우월하거나 비슷하였고 시간 면에서는 기존 방법에 비하여 월등히 우수하였다. 결론:말라리아 진단에 있어 acridine orange 염색법은 예민도가 높고, 조작이 쉽고 시간도 빠르다는 장점이 있어 초보자와 대량 검체의 검사시 선별 검사로서 유용할 것으로 생각되었다. Background: In South Korea, indigenous malaria has been reappeared since 1993 and more than 350 cases diagnosed in 1996. For the diagnosis of malaria the classic methods such as thin and thick blood smears with Giemsa or Wright stain has been routinely used. Since recently fluorochrome staining has been shown to be more sensitive, easy to do, and less time-consuming, we applied the new method, Acridine orange stain, for diagnosis of clinically suspected cases. Methods: Thin and thick blood smears were prepared from civilian patients of Kyunggi Province(n=20) and Republic Of Korea army patients pre(n=67) and posttreatment(n=13) of malaria. The slides were fixed by methanol and stained by either Giemsa or Acridine orange solution(10-50㎍/mL). For comparison, an expert on malaria diagnosis examined them by light and fluorescent microscope, respectively. Result: Acridine orange stain was found to be a rapid technique, and as sensitive(83%) as thick smears(83%) for diagnosis of malaria. The detection limit of acridine orange stain was 23.5 parasites/μ1 of blood. The staining time was much shorter(30 sec) than that of Giemsa stain(30-60min). Conclusion: Acridine orange stain is evaluated as a simple, rapid, and sensitive method for malaria diagnosis, compared with Giemsa stain.