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.

Proposed mechanism in the change of cellular composition in the outer medullary collecting duct during potassium homeostasis.

Park, E-Y,Kim, W-Y,Kim, Y-M,Lee, J-H,Han, K-H,Weiner, I D,Kim, J Gutenberg 2012 HISTOLOGY AND HISTOPATHOLOGY Vol.27 No.12

<P>Potassium depletion (K?-D) induces hypertrophy and hyperplasia of collecting duct cells, and potassium repletion (K?-R) induces regression of these changes. The purpose of this study was to examine the time courses of the changes in cellular composition, the origin of intercalated cells (ICs) and the mechanism responsible for these changes. SD rats received K?-depleted diets for 1, 7, or 14 days. After K?-D for 14 days some of the rats received normal diets for 1, 3, 5, or 7 days. In the inner stripe of the outer medulla, K?-D increased significantly the number and proportion of H?-ATPase-positive ICs, but decreased the proportion of H?-ATPase-negative principal cells (PCs). However, proliferation was limited to H?-ATPase-negative PCs. During K?-R, the cellular composition was recovered to control level. Apoptosis increased during K?-R and exclusively limited in H?-ATPase-negative PCs. Double immunolabeling with antibodies to PC and IC markers identified both cells negative or positive for all markers during both K?-D and K?-R. Electron microscopic observation showed that ultrastructure of AE1-positive some cells were similar to AE1-negative some cells during K?-R. LC3 protein expression increased significantly and autophagic vacuoles appeared particularly in PCs on days 14 of K?-D and in ICs on days 3 of K?-R. These results suggest that PCs and ICs may interconvert in response to changes in dietary K+ availability and that autophagic pathways may be involved in the interconversion.</P>

Stoichiometric Layered Potassium Transition Metal Oxide for Rechargeable Potassium Batteries

Kim, Haegyeom,Seo, Dong-Hwa,Urban, Alexander,Lee, Jinhyuk,Kwon, Deok-Hwang,Bo, Shou-Hang,Shi, Tan,Papp, Joseph K.,McCloskey, Bryan D.,Ceder, Gerbrand American Chemical Society 2018 Chemistry of materials Vol.30 No.18

<P>K-ion batteries are promising alternative energy storage systems for large-scale applications because of the globally abundant K reserves. K-ion batteries benefit from the lower standard redox potential of K/K<SUP>+</SUP> than that of Na/Na<SUP>+</SUP> and even Li/Li<SUP>+</SUP>, which can translate into a higher working voltage. Stable KC<SUB>8</SUB> can also be formed via K intercalation into a graphite anode, which contrasts with the thermodynamically unfavorable Na intercalation into graphite, making graphite a readily available anode for K-ion battery technology. However, to construct practical rocking-chair K-ion batteries, an appropriate cathode material that can accommodate reversible K release and storage is still needed. We show that stoichiometric KCrO<SUB>2</SUB> with a layered O3-type structure can function as a cathode for K-ion batteries and demonstrate a practical rocking-chair K-ion battery. In situ X-ray diffraction and electrochemical titration demonstrate that K<SUB><I>x</I></SUB>CrO<SUB>2</SUB> is stable for a wide K content, allowing for topotactic K extraction and reinsertion. We further explain why stoichiometric KCrO<SUB>2</SUB> is unique in forming the layered structure unlike other stoichiometric K-transition metal oxide compounds, which form nonlayered structures; this fundamental understanding provides insight for the future design of other layered cathodes for K-ion batteries.</P> [FIG OMISSION]</BR>

EFFECTS OF ACUTE AND SUBACUTE ADMINISTRATION OF COCAINE ON DOPAMINERGIC SYSTEMS IN THE RAT STRIATUM

Lim, D.K.,Ho, I.K. The Korean Society of Toxicology Korea Environment 1990 Toxicological Research Vol.6 No.1

The characteristics of dopamine uptake, D-1 and D-2 receptors after acute and subacute cocaine administration were determind in striatum from WKY and SHR. Cocaine was administered either acutely (40 mg/kg, s.c.) or twice daily (20 mg/kg, s.c.) for 3 and 7 days in 9-wk old WKY and SHR. Rats were sacrificed 30 min, 2 or 24 h after the single injection and 18 h after the last administration to the subacutely treated group. The changes in dopamine uptake, dopamine uptake sites, D-1 and D-2 receptors were determined using $(^3H)$dopamine, $(^3H)$-GBR-12935, $(^3H)$SCH-23390 and $(^3H)$sulpiride, respectively. In acutely treated rats, significant increases in $V_{max}$of dopamine uptake were observed 30 min after the cocanine injection in both strains without changes in $K_m$ values. The in vitro $IC_{50}$for cocaine was significantly decreased 30 min in WKY and 2 h in SHR. However, that for in vitro GBR-12909 was significantly increased 30 min and 2 h in both strains. Also densities of $(^3H)$-GBR-12935 binding sites were significantly increased 30 min and 2 h without changes in their $K_d$. Significant increases in D-2 receptor density were observed 30 min, 2 or 24 h after acute injection in both strains without changes in their affinities. The density of D-1 receptor was significantly decreased 30 min after the injection in WKY, but not in SHR. In subacutely treated rats, a significant increase in $K_m$ of dopamine uptake was observed in 7-day treated SHR. The in vitro $IC_{50}$fot GBR-12909 was significantly increased in 3-day treated WKY. The density of D-1 receptors was significantly increased in 3- and 7-day treated WKY, but not in SHR. The affinity of both binding sites remained unchanged. The results suggest that cocanine administration alters dopamine uptake, characteristics of dopamine uptake sites and dopamine receptor binding characteristics in rat brain. Furthermore, D-1 and D-2 dopamine receptors appear to be differently regulated.

RF 스위치 적용을 위한 박막 PZT 엑추에이터의 d<SUB>31</SUB> 구동과 d<SUB>33</SUB> 구동 특성 비교

신민재(M. J. Shin),서영호(Y. H. Seo),최두선(D-S. Choi),황경현(K-H. Hwang) 한국정밀공학회 2006 한국정밀공학회 학술발표대회 논문집 Vol.2006 No.5월

In this work, we present the comparison between d<SUB>31</SUB> and d<SUB>33</SUB> mode characterization using the PZT micro-actuator for large displacement. The PZT micro-actuator consisted of Si, PZT, and Pt layer on SOI wafer. The electrode shapes were laminated and interdigitated for d<SUB>31</SUB> and d<SUB>33</SUB> mode, respectively. In order to characterize the actuation mode, we measured the displacement using laser interferometer. The maximum displacement of d<SUB>31</SUB> mode was 12.2㎛ at 10V, the actuation characterization of d<SUB>31</SUB> was better than that of d<SUB>33</SUB> mode. We estimated that displacement of d<SUB>33</SUB> mode would be larger than that of d<SUB>31</SUB> above 30V.

재래한우의 보존을 위한 혈청 및 혈구단백질의 유전적 다형현상

한상기(S . K . Han),윤희섭(H . S . Yoon),정의룡(E . Y . Chung),신유철(Y . C . Shin),변희대(H . D . Byun) 한국축산학회 1995 한국축산학회지 Vol.37 No.1

Biochemical polymorphisms of five red cell and semen proteins, Hemoglobin(Hb), Transferrin(Tf), Post-transferrin 2(Ptf2), Post-albumin(Pa) and Albumin(Alb) as genetic markers in Korean cattle were analyzed by Starch and Polyacryamide gel electrophoresis and their phenotypes, genotypes and gene frequencies were estimated in order to analysis the genetic constitution of Korean native cattle population. In the Hemoglobin(Hb) locus four different phenotypes AA, AB, BB and CH were observed and assumed to be controlled by four different alleles designated Hb^A, Hb^B, Hb^C and Hb^H, and the Hb^H type was rare variant of Korean native cattle. The observed distribution of phenotypes were 73.37% for AA type, 23.37% for AB type. 2.72% for BB type and 0.54%r for CH type. Gene frequencies of Hb^A, Hb^B, Hb^C and Hb^H were 0.8505, 0.1440, 0.0027 and 0.0027. Semen Transfetrin(Tf) locus, 11 different phenotypes AA, AD₁, AD₂, AE, AH, D₁D₁, D₁D₂, D₁E, D₂H, D₂D₂, D₂E, EE and EH type were identified, which considered to be controlled by codominant alleles TF,^A Tf^D, Tf^D, Tf^E and Tf^H at a single locus. The frequencies of Tf genotypes AD₁, D₁E, D₁D₂, D₂E, AA, AE, D₁D₂, AD₂, D₁D₁, EE, AH, D₂H and EH were found to be 16.30, 13.33, 11.85, 10.37, 9.69, 8.15, 7.41, 9.63, 5.93, 4.44, 1.48, 0.74 and 0.01%, respectively. Gene frequencies of TF^A, Tf^(D1) Tf^(D2) and Tf^H were 0.2741, 0.2704, 0,2333, 0.2074 and 0.0148, respectively. And TfH gene were newly identified in Korean native cattle. Considering Post-transterrin 2 locus, three different phenotypess FF, FS and SS were identified, which considers to he controlled by two alleles Ptf^F and Ptf^S at a single autosomal locus. The frequencies of Rf genotypes FS, FF and SS were found to be 51.06. 36.88 and 12.06%n, respectively and gene frequencies of Ptf^F and Ptf^S were 0.6241 and 0.3759. In the Postalbumin(Pa) locus, three different phenotypes FF, FS and SS type were observed to be genetically controllled by Pa^F and Pa^S gene. And genotypes frequencies FS. FF amd SS type were 48.65, 36.(H and 1_5.32%, respectively. The gene frequencies of Pa^F and Pa^S were 0.6036 and 0.3964. The Albumin(Alb) locus were observed to lack any individual variation. Therefore, this locus were defined to be monomorphic. In comparison of genetic distance and dendogram calculated from the gene frequencies, close relationship was obtained between the Japanese cattle and the Korean cattle.

Measurement of D^*+/- meson production in e⁺/-p scattering at low Q²

ZEUS Collaboration,Chekanov, S.,Derrick, M.,Magill, S.,Miglioranzi, S.,Musgrave, B.,Nicholass, D.,Repond, J.,Yoshida, R.,Mattingly, M.C.K.,Jechow, M.,Pavel, N.,Yagues Molina, A.G.,Antonelli, S.,Antoni North-Holland Pub. Co 2007 Physics letters: B Vol.649 No.2

The production of D<SUP>*+</SUP>/-(2010) mesons in e<SUP>+</SUP>/-p scattering in the range of exchanged photon virtuality 0.05<Q<SUP>2</SUP><0.7 GeV<SUP>2</SUP> has been measured with the ZEUS detector at HERA using an integrated luminosity of 82 pb<SUP>-1</SUP>. The decay channels D<SUP>*+</SUP>->D<SUP>0</SUP>π<SUP>+</SUP> with D<SUP>0</SUP>->K<SUP>-</SUP>π<SUP>+</SUP> and corresponding antiparticle decay were used to identify D<SUP>*</SUP> mesons and the ZEUS beampipe calorimeter was used to identify the scattered electron. Differential D<SUP>*</SUP> cross sections as functions of Q<SUP>2</SUP>, inelasticity, y, transverse momentum of the D<SUP>*</SUP> meson, p<SUB>T</SUB>(D<SUP>*</SUP>), and pseudorapidity of the D<SUP>*</SUP> meson, η(D<SUP>*</SUP>), have been measured in the kinematic region 0.02<y<0.85, 1.5<p<SUB>T</SUB>(D<SUP>*</SUP>)<9.0 GeV and |η(D<SUP>*</SUP>)|<1.5. The measured differential cross sections are in agreement with two different NLO QCD calculations. The cross sections are also compared to previous ZEUS measurements in the photoproduction and DIS regimes.

Relationship between Stress Gene Polymorphisms and Litter Size by AI in Pigs

Jin, H.J.,Kim, I.C.,Wee, M.S.,Yeon, S.H.,Kim, C.D.,Lee, S.S.,Cho, C.Y.,Cho, S.R.,Son, D.S.,Park, C.K. 韓國受精卵移植學會 2007 한국동물생명공학회지 Vol.22 No.4

This study was performed to investigate the relationship between PSS-HSP70 gene polymorphism and artificial insemination (AI) reproductivity in the pigs. The RFLP polymorphism of PSS and the SSCP polymorphisms of HSP70 K1, K3 and K4 PCR product were detected different patterns. In the experiment for AI of fresh semen, spring and fall season showed higher litter size born of 10.89 head than 10.47 head of summer season. Landrace was showed higher litter size of 9.96 head than that of Duroc and Yorkshire (p<0.05). Stress relating PSS and HSP70 polymorphism of PSS-Normal, HSP70 K1-BB, K3-AB, K4-AA showd a highest litter size born of 10.97 head and litter size born alive of 10.69 head than that of the other polymorphisms(p<0.05). In the experiment for AI of frozen semen, effects of season and pig breeds were not showed for litter size born. The stress relating polymorphism of PSS-Carrier, HSP70 K1-BB, K3-BB, K4-AB showed highest litter size born of 11.29 head and litter size born alive of 10.82 head and PSS-Normal, HSP70 K1-BB, K3-AB, K4-AA showed the lowest litter size born of 8.48 head and litter size born alive of 7.33 head than that of the other polymorphisms(p<0.05). These results suggest that AI litter size born for the stress of forzen thawed semen may be affected by PSS and HSP70 polymorphism in pigs.

Protein Profile in Corpus Luteum during Pregnancy in Korean Native Cows

Chung, H.J.,Kim, K.W.,Han, D.W.,Lee, H.C.,Yang, B.C.,Chung, H.K.,Shim, M.R.,Choi, M.S.,Jo, E.B.,Jo, Y.M.,Oh, M.Y.,Jo, S.J.,Hong, S.K.,Park, J.K.,Chang, W.K. Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.11

Steroidogenesis requires coordination of the anabolic and catabolic pathways of lipid metabolism, but the profile of proteins associated with progesterone synthesis in cyclic and pregnant corpus luteum (CL) is not well-known in cattle. In Experiment 1, plasma progesterone level was monitored in cyclic cows (n = 5) and pregnant cows (n = 6; until d-90). A significant decline in the plasma progesterone level occurred at d-19 of cyclic cows. Progesterone level in abbatoir-derived luteal tissues was also determined at d 1 to 5, 6 to 13 and 14 to 20 of cyclic cows, and d-60 and -90 of pregnant cows (n = 5 each). Progesterone level in d-60 CL was not different from those in d 6 to 13 CL and d-90 CL, although the difference between d 6 to 13 and d-90 was significant. In Experiment 2, protein expression pattern in CL at d-90 (n = 4) was compared with that in CL of cyclic cows at d 6 to 13 (n = 5). Significant changes in the level of protein expression were detected in 32 protein spots by two-dimensional polyacrylamide gel electrophoresis (2-DE), and 23 of them were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Six proteins were found only in pregnant CL, while the other 17 proteins were found only in cyclic CL. Among the above 6 proteins, vimentin which is involved in the regulation of post-implantation development was included. Thus, the protein expression pattern in CL was disorientated from cyclic luteal phase to mid pregnancy, and alterations in specific CL protein expression may contribute to the maintenance of pregnancy in Korean native cows.

여러가지 종류의 사료 섬유질을 섭취하는 쥐의 수분 및 Na 대사에 관한 연구

이봉덕,권순기,이수기 ( B . D . Lee,S . K . Kwon,S . K . Lee ) 한국축산학회 1986 한국축산학회지 Vol.28 No.8

The effects of several sources of dietary fiber on the water and sodium (Na) metabolism of rats were investigated. Wheat bran (D2), pure cellulose (D3), and ground rice straw (D4) replaced corn in the control diet (D1) at the level of 10%: pectin (DS), which is water-soluble, replaced corn at 5% level. In the growth trial with 45 female weanling rats (Sprague Dawley strain), the growth rate of DS was significantly (P≤.05) lower than those of D1 and D2. No difference in growth rate was found among D3, D4 and D5. With regard to water intake of growing rats, there was no difference among all treatments. In metabolism trial with 30 adult male rats, the dry matter (DM) digestibilities of D3 and D4 were significantly lower than those of D1, D2 and D5. Similar DM digestibilities were found in D1, D2 and D5. As in the case of growing rats, no difference was found in water intake among five treatments. With regard to water holding capacity (WHC) of feces, D3 and D4 showed significantly larger values than D2. The WHC of D1 and D5 were even lower (P≤.05) than D2. The bulls density (BD) of feces was exactly in the inverse relationship with WHC. The BD of D3 and D4 were significantly smaller than the other treatments. D1 and D5 showed significantly larger BD than did D2. In terms of Na excretion routes of urine and feces, D1 and DS excreted significantly more Na via urine than did D3 and D4. The D2 showed intermediate values in this respect. No difference was found in Na^+ and osmotic concentrations either in plasma or urine among dietary treatments. With regard to plasma clearances, there was no difference among all treatments in C_(Na)^+, C_(osm) anti C_(H₂O), The C_(H₂O) values from all treatments showed negative values, indicating that the rats were removing excess solutes in body fluids via urine. Among the water-insoluble fibers, wheat bran appeared to be less fibrous than pure cellulose or ground rice straw in several respects, i.e., growth rate, feral WHC and BD, and the route of Na excretion. Except that it inhibits the growth rate of young rats, pectin brought about the same effect as did the control diet, indicating that the gut microflora fermented the water-soluble pectin. Different nutritional and physiological effects might be expected from rats fed dietary fibers having different solubility in water.