• Title/Summary/Keyword: Activity stability

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In Vitro Antibacterial Activities of CRB 529, 535, 538, 545 and 550, A New Carbapenem Derivatives (신규 Carbapenem 유도체 CRB 529, 535, 538, 545, 550의 시험관내 항균력 평가)

  • 민관기;김준겸;이홍우;김정우
    • YAKHAK HOEJI
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    • v.39 no.3
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    • pp.215-222
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    • 1995
  • The in vitro antibacterial activities of new carbapenem. CRB 529, 535, 538, 545 and 550 with meropenem and imipenem were compared. CRB 529. 535, 538, 545 and 550 proved to have a broad an tibacterial spectrum. Its in vitro activity against standard 20 strains was almost the same as that of imipenem and slightly higher than that of meropenem. However. against clinical isolated P. aeruginosa, CRB 529, 535, 538, 545 and 550 showed significantly higher activity than imipenem, and also CRB 529, 535, 538, 545 and 550 showed almost the same activity than imipenem and meropenem against 82 clinical isolated strains including S. aureus (MRSA), S. aureus (MSSA), E. faecalis, E. facium, E. coli, P. aeruginosa, K. pneumonia, P. mirabiris, P. stuartii, M. morganii, C. freundii, E. cloacae, S. marcescens and A. calcoaceticus var. anitratus. The stability of CRB 529, 535, 538, 545 and 550 against porcine renal dehydropeptidase-I(DHP-1) was 10 folds higher than that of imipenem and was 3 folds higher than that of meropenem.

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Studies on the Reactive Characteristics of Immobilized Saccharomyces cerevisia in Ethanol Production (Immobilized Saccharomyces cerevisia의 반응특성에 관한 연구)

  • 김성기
    • Journal of Environmental Health Sciences
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    • v.18 no.1
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    • pp.84-94
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    • 1992
  • In an attempt to develop the immobilized biocatalysts based on immobilized Saccharomyces cerevisiae, immobilized yeast was investigated with respect to the conditions affected to ethanol productivities. Saccharomyces cerevisiae was immobilized in the form of the beads by magnetic-calcium alginate, non magnetic-calcium alginate and acrylamide polymerization. Magnetic immobilized yeast, nonmagnetic immobilized yeast and polyacrylamide immobilized yeast were compared in respect of their pH stability, thermostability, heat tolerance, the relation between the concetration of native yeast and retained activity of immobilized yeast, the activity depending on bead size of immobilized yeast, and the effects of magnesium and cobalt on the activities. The more small bead had retained the higher activity for the three kinds of immobilized yeast. In case of 1.0mm diameter of beads, the retained activity was 40~50% for the all groups. The pH stability profile for the immobilized yeast showed a broad range of optimun activity while the native yeast gave a sharp pick for its optimun pH value. The thermostability was at the range of 25~55$^{\circ}$C for the immobilized yeast groups. It was investigated that the influent magnesium and cobalt concentration, and the relative activity have an influent on heat tolerance at steady state. Both protein content released from immobilized yeast and activity of immobilized yeast were changed after activation of immobilized yeast cell.

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Investigation of muscle-specific beef color stability at different ultimate pHs

  • Wu, Shuang;Han, Jina;Liang, Rongrong;Dong, Pengcheng;Zhu, Lixian;Hopkins, David L.;Zhang, Yimin;Luo, Xin
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.12
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    • pp.1999-2007
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    • 2020
  • Objective: This study was aimed to investigate the muscle-specific beef color stability at normal and high ultimate pHs. Methods: The impact of muscle (Longissimus lumborum [LL] vs psoas major [PM]) and pH (normal ultimate pH [Np] vs high pH dark cutting beef [Hp]) on color stability, indicated by basic color traits, metmyoglobin reducing activity (MRA) and oxygen consumption (OC), as well as the lipid oxidation, were determined over 7 days of display at 4℃. Results: Hp-LL had the highest pH (6.92), followed by Hp-PM (6.01), Np-PM (5.76), and Np-LL (5.52). Hp-LL had increased (p<0.05) a, chroma and % oxymyoglobin during display. Hp-LL also had the highest metmyoglobin (MMb) reducing activity and OC among all the samples, thus, the greatest color stability, although very dark throughout storage, with lowest values for lightness (L) and yellowness (b). Np-LL also exhibited relatively high color stability, as a result of its lower % MMb and OC and higher MRA than psoas muscle samples. The 0.2 unit difference of the pH between Hp and Np psoas muscle, resulted in the difference of the color intensity, not the color stability. Interestingly, high pH psoas muscle (Hp-PM) did not have better color stability than Np-PM, and in fact had lower color stability than even Np-LL. The similar level of OC and lipid oxidation cannot explain the difference in color stability between Hp-PM and Np-LL. Conclusion: The Hp does not always show better color stability compared with Np beef, which depends on the muscle type. The balance of MRA and OC is important to keep the color in great intensity and stability in the meantime.

Reaction Stability of the Recombinant Tyrosinase-CNK Originating from the Psychrophilic Marine Microorganism Candidatus Nitrosopumilus Koreensis (호냉성 균주 유래 재조합 티로시나아제 효소, tyrosinase-CNK의 반응 안정성 연구)

  • Choi, Yoo Rae;Do, Hyunsu;Jeong, Dawon;Park, Junetae;Choi, Yoo Seong
    • Clean Technology
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    • v.22 no.3
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    • pp.175-180
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    • 2016
  • Tyrosinases catalyze the hydroxylation of a monophenol (monophenolase activity) and the conversion of an o-diphenol to o-quinone (diphenolase activity), which are mainly involved in the modification of tyrosine residues into 3,4-dihydroxyphenyl-alanine (DOPA) and DOPA/DOPAquinone-derived intermolecular cross-linking. Previously, we obtained a slightly acidic and cold-active tyrosinase, tyrosinase-CNK, by our recombinant protein approach. The enzyme showed optimal activity at pH 6.0 and 20 ℃ with an abnormally high monophenolase/diphenolase activity ratio and still had approximately 50% activity compared with the highest activity even in ice water. Here, we investigated reaction stability of the recombinant tyrosinase-CNK as a psychrophilic enzyme. The enzyme showed remarkable thermal stability at 0 ℃ and the activity was well conserved in repeated freeze-thaw cycles. Although water-miscible organic solvent as reaction media caused the activity decrease of tyrosinase-CNK as expected, the enzyme activity was not additionally decreased with increased concentration in organic solvents such as ethanol and acetonitrile. Also, the enzyme showed high salt tolerance in chaotropic salts. It was remarkably considered that 2+ metal ions might inhibit the incorporation of Cu2+ into the active site. We expect that these results could be used to design tyrosinase-mediated enzymatic reaction at low temperature for the production of catechols through minimizing unwanted self-oxidation and enzyme inactivation.

Studies on the Activity and Stability of Egg White lysozyme (난백 lysozyme의 역가측정과 안정성에 관한 연구)

  • 이성기;유익종;김기성;김영붕
    • Korean Journal of Poultry Science
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    • v.17 no.2
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    • pp.109-114
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    • 1990
  • Enzymatic activity of isolated Lysozyme from egg white by cation ion-exchange chromatography was detected with various methods and stability of lysozyme in solution was studied by heat and pH treatments. Lysozyme activity refered to mg pure lysozyme/mg sample was more accurate although it needed standard lysozyme. But lysozyme activity refered to units/mg sample could be detected easily and reducted total detection time. Enzymatic activity of isolated lysozyme which dissolved in 0.066M phosphate buffer(pH 6.3) and then incubated at $37^{\circ}C$ for 2hr was increased remarkably on the lysis of Micrococcus lysodeikticus. The activity of isolated lysozyme by CM Sephadex C-25 was higher in eluting solution of above O. D. 1.0 at 640nm and attained 36, 000 units/mg solid. The stability of isolated lysozyme was decreased by various heat treatment. Activity began to decrease above 6$0^{\circ}C$ and dropped rapidly at $100^{\circ}C$. Especially, 35% loss of activity occured in 0.066M phosphate buffer at $100^{\circ}C$. for 15min. The stability of lysozyme was also affected by pH. lysozyme was very stable in acidic solution but in alkaline solution. Enzymatic activity showed maximum value at pH 3.0 solution while decreased rapidly above pH 6.0 solution.

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Role of the surface loop on the structure and biological activity of angiogenin

  • Jang, Seung-Hwan;Song, Hyang-Do;Kang, Dong-Ku;Chang, Soo-Ik;Kim, Min-Kyung;Cho, Kwang-Hwi;Scherga, Harold A.;Shin, Hang-Cheol
    • BMB Reports
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    • v.42 no.12
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    • pp.829-833
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    • 2009
  • Angiogenin is a member of the ribonuclease superfamily that induces the formation of new blood vessels. It has been suggested that the surface loop of angiogenin defined by residues 59-71 plays a special role in angiogenic function (1); however, the mechanism of action is not clearly defined. To elucidate the role of the surface loop on the structure, function and stability of angiogenin, three surface loop mutants were produced in which 14 amino acids in the surface loop of RNase A were substituted for the 13 amino acids in the corresponding loop of angiogenin. The structure, stability and biological functions of the mutants were then investigated using biophysical and biological approaches. Even though the substitutions did not influence the overall structure of angiogenin, they affected the stability and angiogenic function of angiogenin, indicating that the surface loop of angiogenin plays a significant role in maintaining the stability and angiogenic function of angiogenin.

Effect of Balance Training on Ankle Muscle Activity and Static Balance in Stroke Patients (균형훈련이 뇌졸중환자의 발목 근육 활성도와 정적균형에 미치는 영향)

  • Lee, Young-Min;Kim, Sang-Chul;Yoon, Sung-Kyeung
    • PNF and Movement
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    • v.12 no.4
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    • pp.209-215
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    • 2014
  • Purpose: This study aims to understand the effect of balance training on ankle muscle activity and static balance in stroke patients. Methods: The subjects were composed of 12 patients who were admitted with chronic stroke in H, K, and R hospitals located in Gangwon-do from August to October 2014. This study conducted balance training on the subjects for 20 min a session, twice a day, five times a week for six weeks. This study measured the surface electromyogram (EMG) of the paretic side's tibialis anterior and medial gastrocnemius for muscle activity. Static balance was measured as a TETRAX stability index. The measurements were conducted before the experiment and six weeks after. The result was statistically analyzed using paired t-test at the significance level of 0.05. Result: Muscle activity of the paretic side's tibialis anterior and medial gastrocnemius did not show a significant difference in the comparison between pre- and post-balancing training. However, the stability index showed a significant difference (p<0.05) between standing with eyes open (NO) and standing on a sponge with eyes open (PO). Conclusion: Although balance training did not affect the muscle activity of chronic stroke patients, it had an effective influence on the stability index. That is, balance training was effective at the functional level, but it did not change the structure level in terms of the ICF evaluation standard. Balance training becomes more effective when it is applied in relation to task.

Modification of Hepatic Microsomal Cytochrome P450 2E1 Enzyme by Garlic Powder in Rat Hepatocarcinogenesis

  • Park, Kyung-Ae;Choi, Hay-Mie
    • BMB Reports
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    • v.30 no.1
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    • pp.73-79
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    • 1997
  • This study was designed to investigate the effects of dietary garlic powder on cytochrome P450 enzymes and membrane stability in murine hepatocarcinogenesis initiated by diethylnitrosamine (DEN). Male Sprague-Dawley rats received a single intraperitoneal injection of DEN (200 mg/kg body wt) dissolved in saline. After 2 weeks on a basal diet, animals were fed diets containing 0. 0.5. 2.0. or 5.0% garlic powder for 6 weeks, and were subjected to two-thirds partial hepatectomy. The areas of placental glutathione S-transferase (GST-P) positive foci were inhibited in rats fed with garlic diets. GST-P is the most effective marker for DEN-initiated lesions. Hepatic microsomal lipid peroxidation was significantly decreased in rats fed with 2.0 and 5.0% garlic powder diets compared with that observed in the control animals and hepatic microsomal glucose 6-phosphatase (G6Pase) activity was found to increase significantly in rats fed 0.5 and 2.0% garlic powder diets. Thus as little as 0.5% garlic powder has a positive effect on the stability of hepatic microsomal membranes. p-Nitrophenol hydroxylase (PNPH) activity and the level of cytochrome P450 2E1 protein in the hepatic microsomes from rats fed diets containing 2.0 and 5.0% garlic powder were much lower than those of control microsomes. Rats fed 5.0% garlic powder diets exhibited the lowest P450 2E1 activity and protein levels among groups. Pentoxyresorufin O-dealkylase activity and immunoblot (cytochrome P450 2B1) analyses were not different between groups. However, the levels of cytochrome P450 1A1/2 protein in rats fed 0.5 and 2.0% garlic powder were significantly induced compared to controls. These results suggest that 2.0% garlic powder is effective in inhibiting the areas of GST-P positive foci, modulating certain isoforms of cytochrome P450 enzymes and stabilizing the hepatic microsomal membrane. Thus, the selective modification of cytochrome P450 enzymes and membrane stability by dietary garlic powder may influence areas of GST-P positive foci and chemoprevention of post-initiation of rat hepatocarcinogenesis.

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Development of W/O/W Multiple Emulsion Formulation Containing Burkholderia gladioli

  • KIM, HWA-JIN;CHO, YOUNG-HEE;BAE, EUN-KYUNG;SHIN, TAEK-SU;CHOI, SUNG-WON;CHOI, KEE-HYUN;PARK, JI-YONG
    • Journal of Microbiology and Biotechnology
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    • v.15 no.1
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    • pp.29-34
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    • 2005
  • W/O/W (water-in-oil-in-water) type multiple emulsion was applied to improve the storage stability of an antagonistic microorganism, Burkholderia gladioli. Encapsulation of microorganism into a W/O/W emulsion was conducted by using a two-step emulsification method. W/O/W emulsion was prepared by the incorporation of B. gladioli into rapeseed oil and the addition of polyglycerin polyriconolate (PGPR) and castor oil polyoxyethylene (COG 25) as the primary and secondary emulsifier, respectively. Microcrystalline cellulose was used as an emulsion stabilizer. To evaluate the usefulness of W/O/W emulsion formulation as a microbial pesticide for controlling the bacterial wilt pathogen (Ralstonia solanacearum), the storage stability and antagonistic activity of emulsion formulation were tested in vitro. The storage stability test revealed that the viability of formulated cells in emulsion was higher than that of unformulated cells in culture broth. At $4^{\circ}C$, the viabilities of formulated cells and unformulated cells at the end of 20 weeks decreased to about 2 and 5 log cycles, respectively. At $37^{\circ}C$, the viability of formulated cells decreased to only 2 log cycles at the end of storage. On the other hand, the viable cells in culture broth were not detected after 13 weeks. In activity test, formulated cells in emulsion were more effective in inhibiting the growth of pathogen than unformulated cells in culture broth. Unformulated cells completely lost their antagonistic activity during storage under similar conditions. The W/O/W multiple emulsion formulation was shown to be useful as the novel liquid formulation for biological control.

Effects of self stretching exercise and movement with mobilization in lunge position on the muscle activity and balance in chronic stroke patients (런지자세에서의 자가 신장운동과 능동운동을 동반한 가동술이 만성 뇌졸중 환자의 근활성도 및 균형에 미치는 영향)

  • Jeong, Yong-Sik
    • Journal of Digital Convergence
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    • v.11 no.10
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    • pp.549-556
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    • 2013
  • In this study, we investigated the effects of stretching and movement with mobilization in lunge position on the muscle activity of the lower limb and limited of stability in chronic stroke patients with hemiplegia. Sixteen subjects were randomly selected and classified into the experimental and control groups. The experimental group performed self stretching exercises in the lunge position, and in the control group performed movement with mobilization in the lunge position. The interventions were conducted for 20 min, 5 times a week for 8 weeks. Statistical analyses were performed using repeated ANOVA. The analysis results showed no statistically significant between-group differences with respect to the muscle activity(%MVIC;maximum voluntary isometric contraction) of lower limb and limited of stability(LOS)(p>.05). However, statistically significant within-group differences were observed in the maximum voluntary isometric contraction and limited of stability for both the groups (p<.05). Therefore, self stretching in the lunge position is considered to have positive influences on the muscle strength and balance in stroke patients with hemiplegia.