• Title/Summary/Keyword: optimum properties

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Phosphorylation Properties of Recombinant OsCPK11, a Calcium-dependent Protein Kinase from Rice (벼의 칼슘-의존적 단백질 카이네즈인 재조합 OsCPK11의 인산화 특성)

  • Cho, Il-Sang;Lee, Su-Hee;Park, Chung-Mo;Kim, Sung-Ha
    • Journal of Life Science
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    • v.27 no.12
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    • pp.1393-1402
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    • 2017
  • In plants, calcium ($Ca^{2+}$)-dependent protein kinases (CDPKs) are important sensors of $Ca^{2+}$ signals. Previous research demonstrated the expression of the OsCPK11 gene in various tissues at the transcription level, but its developmental and biochemical functions at the protein level were not determined. This study was aimed to identify biochemical characteristics of OsCPK11. GST- OsCPK11 was expressed in E. coli and used for an in vitro kinase assay. Biochemical analyses identified OsCPK11 as a CDPK. OsCPK11 autophosphorylated itself and transphosphorylated histone III-s and MBP as substrates in the presence of $Ca^{2+}$. The activity of the recombinant OsCPK11 was influenced by $Mg^{2+}$, with optimum activity detected at pH 7.0-7.5. OsCPK11 activity was not affected by $Mg^{2+}$, $Mn^{2+}$, or $Na^+$ in the presence of a high level of $Ca^{2+}$. Autophosphorylation of OsCPK11 decreased $Ca^{2+}$ sensitivity of OsCPK11. An anti-OsCPK11 rabbit antibody recognized 95.5 kD of GST-OsCPK11, as shown by an immunoblot analysis. These results shed light on the function of OsCPK11 in $Ca^{2+}$-mediated signaling in rice.

Effect of Al2O3 Inter-Layer Grown on FeCrAl Alloy Foam to Improve the Dispersion and Stability of NiO Catalysts (NiO 촉매의 분산성 및 안정성 향상을 위하여 FeCrAl 합금 폼 위에 성장된 Al2O3 Inter-Layer 효과)

  • Lee, Yu-Jin;Koo, Bon-Ryul;Baek, Seong-Ho;Park, Man-Ho;Ahn, Hyo-Jin
    • Korean Journal of Materials Research
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    • v.25 no.8
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    • pp.391-397
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    • 2015
  • NiO catalysts/$Al_2O_3$/FeCrAl alloy foam for hydrogen production was prepared using atomic layer deposition (ALD) and subsequent dip-coating methods. FeCrAl alloy foam and $Al_2O_3$ inter-layer were used as catalyst supports. To improve the dispersion and stability of NiO catalysts, an $Al_2O_3$ inter-layer was introduced and their thickness was systematically controlled to 0, 20, 50 and 80 nm using an ALD technique. The structural, chemical bonding and morphological properties (including dispersion) of the NiO catalysts/$Al_2O_3$/FeCrAl alloy foam were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy and scanning electron microscopy-energy dispersive spectroscopy. In particular, to evaluate the stability of the NiO catalysts grown on $Al_2O_3$/FeCrAl alloy foam, chronoamperometry tests were performed and then the ingredient amounts of electrolytes were analyzed via inductively coupled plasma spectrometer. We found that the introduction of $Al_2O_3$ inter-layer improved the dispersion and stability of the NiO catalysts on the supports. Thus, when an $Al_2O_3$ inter-layer with a 80 nm thickness was grown between the FeCrAl alloy foam and the NiO catalysts, it indicated improved dispersion and stability of the NiO catalysts compared to the other samples. The performance improvement can be explained by optimum thickness of $Al_2O_3$ inter-layer resulting from the role of a passivation layer.

Purification and Properties of Extracellular Adenine Deaminase from Nocardioides sp. J-257L (Nocardioides sp. J-275L이 생산하는 세포외 Adenine Deaminase의 정제 및 성질)

  • 전홍기;박정혜;김태숙
    • Korean Journal of Microbiology
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    • v.25 no.3
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    • pp.221-228
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    • 1987
  • The extracellular adenine deaminase from Nocardioides sp. J-275L was purified by the following techniques: ammonium sulfate fractionation, DEAE-Cellulose, DEAE-Sephadex A-50 column chromatography, and Sephacryl S-200 superfine gel filtration. The enzyme was partially purified about 3889.5-fold with about 5.2% yield by these procedures. The molecular weight of the enzyme was 39,000 by a calibrated Sephacryl S-200 superfine column chromatography. The enzyme was stable at pH 7.5 and up to $40^{\circ}C$. Glycerol was effective on the stabilization of the enzyme during storage. The optimum pH and temperature of the enzyme were around pH 7.5 and $40^{\circ}C$, respectively. The apparent Michaelis constant Km of the enzyme for adenine was $7.4\times 10^{-5}$M. The purine analogues, 6-chloropurine, 2,6-diaminopurine, 6-bromopurine, 4-aminopyrazolo [3.4-d]pyrimidine, and 8-azaadenine were substrates for the enzyme. 6-Dimethylaminopurine was a competitive inhibitor of the enzyme. The enzyme was inhibited by 1mM of $Cu^{2+}, Fe^{3+}, Pb^{2+}, Hg^{2+}$, and $Ag^{+}$, and 1mM of $\alpha$,$\alpha$'-dipyridyl, pentachlorophenol, and pCMB.

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Characterization and Selection of Lactic Acid Bacteria Producing ${\beta}-Galactosidase$ (${\beta}-Galactosidase$ 생산 유산균 선별 및 특성 조사)

  • Lee, Young-Ki;Choi, Susanna;Park, Young-Il;Park, Chan-Sun;Yoon, Byung-Dae;Hwang, Yun-Sik;Kim, Hee-Sik
    • Korean Journal of Microbiology
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    • v.42 no.3
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    • pp.216-222
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    • 2006
  • This study was carried out to select the lactic acid bacteria producing ${\beta}-galactosidase$ (lactase) and investigate the properties of the ${\beta}-galactosidase$. About 100 strains of lactic acid bacteria showing blue colony on the MRS agar medium containing X-gal were isolated from several kinds of Kimchi. Among them, 2 strains were selected as potential ${\beta}-galactosidase$ producers. The selected strains, ET-1 and LA-12, were identified as Lactobacillus fermentum and L. acidophilus, respectively by the analysis of 16S rDNA sequences. They showed relatively high ${\beta}-galactosidase$ activity and cellular viability. Their ${\beta}-galactosidase$ showed the highest activity at $55^{\circ}C$. And the optimum pHs of the enzymes produced by ET-1 and LA-12 were pH 5.5 and pH 7.0, respectively. They were also highly resistant to artificial gastric juice and bile. Two selected strains showed little change of viable cell number for 3 hr incubation in artificial gastric juice, and maintained the viable cell number at $10^8CFU/ml$ for 24 hr in 0.3% oxgall after incubation for 2 hours in artificial gastric juice. Based on these results, ET-1 and LA-12 are expected to be applied in dairy industry.

Synthesis and After-Glow Characteristics of Eu Activated Sr-Al-O Long Phosphorescent Phosphor (Eu 부활형 Sr-Al-O 계 장잔광 형광체의 합성과 잔광특성)

  • Lee, Young-Ki;Kim, Jung-Yeul;Kim, Byung-Kyu;Yu, Yeon-Tae
    • Korean Journal of Materials Research
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    • v.8 no.8
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    • pp.737-743
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    • 1998
  • The synthesis of $SrAI_2O_4:Eu^{2+}$ phosphor and its properties of both photoluminescence and long-phosphorescent were investigated as a function of sintering condition. Single phase of $SrAl_2O_4$ was obtained by sintering the mixtures of $SrCO_3$, $Eu_2O_3$, $AI_2O_34 and 3wt% $B_2O_3$ powders over 100$0^{\circ}C$ in Ar/H2 atmosphere. The optimum sintering condition for the long-phosphorescent phosphor of $SrAI_2O_4:Eu^{2+}$ was found at 130$0^{\circ}C$ for 3hours. The PL emission spectrum of $SrAI_2O_4:Eu^{2+}$ shows a maximum peak intensity at 520nm(2.384eV) with a broad emission extending from 450 to 650nm which resulted from the $4f^65d^1$$\rightarrow$$4f^7$ transition of $Eu^{+2}$ under 360nm exitation. Monitored at 520nm. the excita¬tion spectrum of $SrAI_2O_4:Eu^{2+}$ exhibits a maximum peak intensity at 360nm (3.44eV) with a broad absorption band extending from 250 to 480nm.

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Isolation of Mutant Strains from Keratinase Producing Bacillus subtilis SMMJ-2 and Comparision of Their Enzymatic Properties (Keratinase 생산균 Bacillus subtilis SMMJ-2의 변이주 분리와 효소학적 특성 비교)

  • Ko, Hee-Sun;Kim, Hyun-Soo
    • KSBB Journal
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    • v.25 no.5
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    • pp.429-436
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    • 2010
  • Keratinase is widely used in certain industrial applications. The present study sought to improve the culture conditions of Bacillus subtilis SMMJ-2 to facilitate mass production of keratinase. Strain SMMJ-2 was irradiated by ultraviolet light and the resulting isolates were tested for keratinase activity. Isolates displaying elevated keratinase activity were selected and used to determine the optimum temperature (24, 30, 37, 45, $55^{\circ}C$) for bacterial keratinase production during a 4 day incubation period. The highest enzyme activity (55 units/mL/min), from a Bacillus subtilis SMMJ-2 mutant (mutant No. 2) was demonstrated following incubation at $30^{\circ}C$. The effects of carbon and nitrogen sources on keratinase production were confirmed by measuring the enzyme activity from the culture broth of the mutant strain cultured in various media containing different carbon source and nitrogen sources during a 4 day period. The optimal medium composition for producing keratinase consisted of 1% glucose, 0.7% $K_2HPO_4$, 0.2% $K_2HPO_4$, and 1.2% soybean meal. Optimal initial pH and temperature for producing keratinase were 7.0 and $30^{\circ}C$, respectively. Keratinases produced by B. subtilis SMMJ-2 and the mutant No. 2 were purified from the culture broth which used soybean meal as a nitrogen source. Membrane ultrafiltration, DEAE-sephacel ion exchange and Sephadex G-100 gel chromatography were used to purify the enzymes. The purified keratinases from both B. subtilis SMMJ-2 and the mutant No. 2 showed single bands and their molecular weights were estimated as 28 kDa and 42 kDa, respectively on SDS-polyacrylamide gel electrophoresis.

The Effects of Pretreatment and Surfactants on CNT and Permalloy Composite Electroplating (전처리와 분산제가 CNT-permalloy 복합전기도금에 미치는 영향 연구)

  • Um, Ho-Kyung;Lee, Heung-Yeol;Yim, Tai-Hong;Lee, Jae-Ho
    • Journal of the Microelectronics and Packaging Society
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    • v.17 no.1
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    • pp.63-68
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    • 2010
  • CNT and permalloy composite plating was investigated. CNTs were pretreated prior to electroplating to disassemble the tangled CNT lumps. The ball milling as a physical pretreatment and the acid treatment as a chemical pretreatment were used. 10M nitric acid and 10 M sulfuric acid were used for the chemical pretreatment. Sulfuric acid was more effective than nitric acid to disassemble CNT lumps. To disperse CNT in the solution, surfactants were used. SDS, Triton X-100 and PAA were used for this purpose. More CNTs were incorporated in permalloy coating when PAA was used as a surfactant. The surface morphologies were observed with FESEM after electroplating CNT and permalloy. The current densities were varied from 10 to $80\;mA/cm^2$ and the concentration of PAA was fixed at 2 g/L. The optimum current density without surface cracks was $20\;mA/cm^2$. The crystallinity of the deposit was analyzed with XRD and the surface hardness was analyzed with Vicker's hardness tester. The corrosion behavior was analyzed with polarization plot. The physical properties of permalloy were not improved with CNT composite plating.

Mechanical Properties and Field Implementation of Floor Mortar Incorporated with VAE Polymer (VAE 폴리머를 이용한 모르타르 바닥재의 역학적 특성과 현작 적용성)

  • Bang, Jin-Wook;Lee, Sun-Mok;Kim, Yun-Yong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.3
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    • pp.27-34
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    • 2017
  • Recently, the importance of the industrial warehouse floor has been increasing due to the development of the distribution and logistics industry. In this present study, an early-hardening polymer floor mortar which can compensate for the limitation of conventional cement based floor mortar regarding fluidity and long curing time was developed. In order to achieve the early-hardening of mortar characteristic ultra rapid hardening cement was used as binder. Four types of mixture proportions in accordance with the vinyl acetate ethylene(VAE) polymer contents with range from 10% to 20% and the other proto proportion without VAE polymer were designed. Mechanical experiments including the fluidity test, compressive strength test, bending test, bond test, and abrasion test were conducted for all mixture proportions. From the flow test result, it was possible to achieve the high flow with 250 mm by controlling the amount of superplasticizer. The incorporation of VAE polymer was found to affect the compressive strength reduction, however, the flexural strength was higher than that of the proto mixture, and it was evaluated to increase the compressive strength / flexural strength ratio. Moreover, at least 2.6 times higher bond strength and more than 4 times higher abrasion resistance were secured. From the mechanical experiments results, the optimum mixing ratio of the VAE polymer was determined to be 10%. As a result of application and monitoring, it shows that it has excellent resistance to cracking, discoloration, impact, and scratch as well as bond performance compared to the cement based floor mortar.

The Physical Property of the Structural Color Yarn and Fabric for Emotional Garment Using Biomimetic Technology (생체모방기술을 응용한 감성의류용 구조발색사와 직물의 물성)

  • Kim, Hyun-Ah;Kim, Seung-Jin
    • Science of Emotion and Sensibility
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    • v.15 no.1
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    • pp.141-148
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    • 2012
  • This study investigated the structural coloration and fabric hand of the caustic reduced fabrics for emotional garment using structural color yarns, which was spun by 37 alternating nylon and polyester layers capable of producing basic colors using biomimetic technology. The colorations of the three kinds of structural color yarns were confirmed using multi angle spectro-photometer, and their triangular cross sections composed with 37 alternating nylon and polyester layers were measured using SEM and were discussed with layer length in relation with coloration and spinning conditions were also set up. The apparent color difference and reflectance of the three kinds of fabrics with different density and weave pattern were analysed as ranging from 400nm to 700nm. The optimum fabric structural design which is made by warp and weft densities(194ends/in ${\times}$ 105picks/in) and caustic reduction condition by $100^{\circ}C$ temperature and 60minutes with NaOH, 20g/l solution were decided through analysis of the mechanical properties and fabric hands of these three kinds of fabrics treated with 3 kinds of the caustic reduction conditions. And it was shown that the rate of caustic reduction was increased from 13% to 23% with increasing temperature and time of caustic reduction. The extensibility, bending rigidity and shear modulus of caustic reduction treated fabrics were decreased by treatment of caustic reduction, on the other hand fabric compressibility was increased. And it was shown that the hand value of specimen number one which was treated with temperature $100^{\circ}C$ and time 60minute was the best and the hand of this fabric was better than that of Morpho $fabric^{(R)}$ made by Teijin co. Japan.

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Manufacture of Functional Yogurt supplemented with Crude Materials extracted from Kaempferia parviflora

  • Kang, Soo-Hyun;Kim, Soo-Ki;Kim, Dong-Hyeon;Kim, Hong-Seok;Lee, Soo-Kyung;Song, Kwang-Young;Yim, Jin-Hyuk;Kim, Young-Ji;Kang, Il-Byung;Jeong, Dana;Park, Jin-Hyeong;Jang, Ho-Seok;Chon, Jung-Whan;Kim, Hyunsook;Seo, Kun-Ho
    • Journal of Dairy Science and Biotechnology
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    • v.34 no.3
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    • pp.181-186
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    • 2016
  • Kaempferia parviflora (Krachaidam, Zingiberaceae) is used as a traditional Thai medicine for treating various ailments, including allergy, fatigue, sexual dysfunction, and ulcer. Moreover, it is also used to promote longevity and as a nerve tonic. The aim of this study was to develop functional yoghurt containing Kaempferia parviflora and to examine the physicochemical characteristics of yoghurt supplemented with different concentration of K. parviflora. To this end, we examined the pH and sensory evaluation of yoghurt containing K. parviflora. The pH of this yoghurt decreased whereas the TA increased with incubation time (up to 5 h) without altering the amounts of K. parviflora added. In the sensory evaluation, the taste, flavor, color, and overall acceptability decreased in proportion to the amount of K. parviflora added. Among the experimental group, high scores were achieved by yoghurt containing 1% K. parviflora compared with that by the control group. We conclude there is an urgent need for additional research on the production of this multi-functional yogurt (with properties including anti-obesity and anti-inflammatory), using an optimum concentration of K. Parviflora.