• Title, Summary, Keyword: kinetics

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Inhibitory Effects of Four Solvent Fractions of Alnus firma on α-Amylase and α-Glucosidase. (사방오리나무 추출물의 α-amylase 및 α-glucosidase 저해활성)

  • Choi, Hye-Jung;Jeong, Yong-Kee;Kang, Dae-Ook;Joo, Woo-Hong
    • Journal of Life Science
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    • v.18 no.7
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    • pp.1005-1010
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    • 2008
  • In this study, we investigated the inhibitory effect of four solvent fractions of Alnus firma on ${\alpha}-amylase$, ${\alpha}-glucosidase$ and aldose reductase activities. The inhibitory test showed that methanol (MeOH) extract and hexane (HX) fraction strongly inhibited pork pancreatin and salivary ${\alpha}-amylase$ activity. The MeOH extract and HX fraction of Alnus firma at the concentration of 4 mg/ml inhibited more than 70% of pancreatin and salivary ${\alpha}-amylase$ activity. The inhibitory effect of fractions has different specificities against ${\alpha}-amylase$ from pancreatin and salivary. In addition, the MeOH extract and butanol (BuOH) fraction showed the highest inhibitory activity on yeast ${\alpha}-glucosidase$ at values of $IC_{50}$ $137.36\;{\mu}g/ml$ and $115.14\;{\mu}g/ml$ respectively. The MeOH extract and BuOH fraction showed the highest inhibitory activity on yeast ${\alpha}-glucosidase$ than commercial agent such as 1-deoxynorjirimycin and acarbose. Inhibition kinetics of solvent fractions showed that ${\alpha}-glucosidase$ has been inhibited noncompetitively by the MeOH, EA and BuOH fraction. The aldose reductase from human muscle cell had been inhibited strongly by the MeOH extract and EA fraction at 57.996% and 83.293% at the concentration of $50\;{\mu}g/ml$, respectively. These findings may contribute to biological significance in that ${\alpha}-amylase$, ${\alpha}-glucosidase$ and aldose reductase inhibitory compounds could be used as a functional food and a drug for the symptomatic treatment of antidiabetic disease in the future.

Expression and Purification of the Phosphatase-like Domain of a Voltage-Sensing Phosphatase, Ci-VSP (막 전위 감지 탈인산화 효소, Ci-VSP의 유사 탈인산화 효소 도메인의 발현과 정제)

  • Kim, Sung-Jae;Kim, Hae-Min;Choi, Hoon;Kim, Young-Jun
    • Journal of Life Science
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    • v.21 no.7
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    • pp.1032-1038
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    • 2011
  • Recently identified Ciona intestinalis voltage sensor-containing phosphatase (Ci-VSP) consists of an ion channel-like transmembrane domain (VSD) and a phosphatase-like domain. Ci-VSP senses the change of membrane potential by its VSD and works as a phosphoinositide phosphatase by its phosphatase domain. In this study, we present the construction of His-tagged phosphatase-like domain of Ci-VSP, its recombinant expression and purification, and its enzymatic activity behavior in order to examine the biochemical behavior of phosphatase domain of Ci-VSP without interference. We found that Ci-VSP(248-576)-His can be eluted with an elution buffer containing 25 mM NaCl and 100 mM imidazole during His-tag purification. In addition, we found the proper measurement condition for kinetics study of Ci-VSP(248-576)-His against p-nitrophenyl phosphate (pNPP). We measured the kinetic constant of Ci-VSP(248-576)-His at $37^{\circ}C$, pH 5.0 or 5.5, under 30 min of reaction time, and less than $2.0\;{\mu}g$ of protein amount. With these conditions, we acquired that Ci-VSP(248-576)-His has $K_m$ of $354{\pm}0.143\;{\mu}M$, $V_{max}$ of $0.0607{\pm}0.0137\;{\mu}mol$/min/mg and $k_{cat}$ of $0.359{\pm}0.009751\;min^{-1}$ for pNPP dephosphorylation. Therefore, we produced a pure form of Ci-VSP(248-576)-His, and this showed a higher activity against pNPP. This purified protein will provide the road to a structural investigation on an interesting protein, Ci-VSP.

Characterization of an Ion Channel Prepared from Tomato Roots and Inhibitory Effects by Heavy Metal Ions (토마토 뿌리조직에서 분리한 이온채널의 중금속에 의한 저해)

  • Shin, Dae-Seop;Han, Min-Woo;Kim, Young-Kee
    • Applied Biological Chemistry
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    • v.47 no.4
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    • pp.390-395
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    • 2004
  • In order to characterize ion channels present in tomato roots, microsomes were incorporated into an artificial lipid bilayer arranged for electrophysiological analysis. Of the five different ion channels that could be found, a channel of 450 pS conductance was found most frequently. This channel displayed subconductance states of 450, 257 and 105 pS. All subconductance states showed linear current-voltage relationships. At positive holding potentials, high frequency of transient channel openings was observed; however, at negative potentials, the open times were long and open probability high. Po was 0.83 at -40 mV. When an additional 50 mM $K^+\;or\;Na^+$ was added to the cis side of bilayer, the reversal potentials shifted in the negative direction to near -10 mV. Thus, the 450 pS cation channel selects poorly between $K^+\;and\;Na^+$. In the presence of $100\;{\mu}M$ metal ions, the channel activity was severely inhibited by $La^{3+},\;Ba^{2+},\;and\;Zn^{2+}$, and Po was decreased to 0.2 or even less. However, $Al^{3+}\;and\;Cd^{2+}$ decreased the activity by only 20%. Interestingly, each metal ion showed different kinetics of channel inhibition. While $500\;{\mu}M\;La^{3+}$ inhibited the activities of all subconductance state, 1 mM $Zn^{2+}$ inhibited all except the 105 pS state. $Cd^{2+}$ changed the gating of the channel from a long-opening state to brief transient openings even at negative holding potentials. These data represent that the metal ions may have different binding sites on the channel protein and could be useful modulators and probes to investigate structural characteristics as well as the functional roles of the 450 pS channel on the root physiology.

Gait Analysis of a Pediatric-Patient with Femoral Nerve Injury : A Case Study (대퇴신경 손상 환아의 보행분석 : 사례연구)

  • Hwang, S.H.;Park, S.W.;Son, J.S.;Park, J.M.;Kwon, S.J.;Choi, I.S.;Kim, Y.H.
    • Journal of Biomedical Engineering Research
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    • v.32 no.2
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    • pp.165-176
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    • 2011
  • The femoral nerve innervates the quadriceps muscles and its dermatome supplies anteromedial thigh and medial foot. Paralysis of the quadriceps muscles due to the injury of the femoral nerve results in disability of the knee joint extension and loss of sensory of the thigh. A child could walk independently even though he had injured his femoral nerve severely due to the penetrating wound in the medial thigh. We measured and analyzed his gait performance in order to find the mechanisms that enabled him to walk independently. The child was eleven-year-old boy and he could not extend his knee voluntarily at all during a month after the injury. His gait analysis was performed five times (GA1~GA5) for sixteen months. His temporal-spatial parameters were not significantly different after the GA2 or GA3 test, and significant asymmetry was not observed except the single support time in GA1 results. The Lower limb joint angles in affected side had large differences in GA1 compared with the normal normative patterns. There were little knee joint flexion and extension motion during the stance phase in GA1 The maximum ankle plantar/dorsi flexion angles and the maximum knee extension angles were different from the normal values in the sound side. Asymmetries of the joint angles were analyzed by using the peak values. Significant asymmetries were found in GA1with seven parameters (ankle: peak planter flexion angle in stance phase, range of motion; ROM, knee: peak flexion angles during both stance and swing phase, ROM, hip: peak extension angle, ROM) while only two parameters (maximum hip extension angle and ROM of hip joint) had significant differences in GA5. The mid-stance valleys were not observed in both right and left sides of vertical ground reaction force (GRF) in the GA1, GA2. The loading response peak was far larger than the terminal stance peak of vertical ground reaction curve in the affected side of the GA3, GA4, GA5. The measured joint moment curves of the GA1, GA2, GA3 had large deviations and all of kinetic results had differences with the normal patterns. EMG signals described an absence of the rectus femoris muscle activity in the GA1 and GA2 (affected side). The EMG signals were detected in the GA3 and GA4 but their patterns were not normal yet, then their normal patterns were detected in the GA5. Through these following gait analysis of a child who had selective injuries on the knee extensor muscles, we could verify the actual functions of the knee extensor muscles during gait, and we also could observe his recovery and asymmetry with quantitative data during his rehabilitation.

The Effect of Cold Shock on Function and Morphology of Dog Epididymal Spermatozoa (개에서 cold shock이 정소상체유래의 정자의 기능과 형태에 미치는 영향)

  • Yu Il-jeoung
    • Journal of Veterinary Clinics
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    • v.21 no.4
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    • pp.329-335
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    • 2004
  • Dog spermatozoa were recovered from the caudae epididymides of 23 domestic dogs which were 11 pure breed and 12 mix-breed dogs ranging in age from 0.6 to 3 years. The experimental designs were as follows: 1) the effect of chilling to 0. 10 or 37$^{\circ}C$. 2) the kinetics of chilling injury at 0 or 4$^{\circ}C$, and 3) the effect of sugars at $0^{\circ}C$. Viable spermatozoa were recovered by percoll gradient separation and adjusted to 5${\times}$10$^{7}$ spermatozoa/ml. In experiment 1, spermatozoa were diluted with 0.33 M glucose supplemented with 3% BSA (G-BSA) at 1:2 dilution. Spermatozoa were loaded into straws and exposed at 0, 10 or 37$^{\circ}C$ for 30 min. In experiment 2, spermatozoa were prepared as the experiment 1 and exposed for 0.5, 5, 15, or 30 min at 0 or 4$^{\circ}C$. In experiment 3, spermatozoa were diluted with different sugars (0.33 M galactose, glucose, fructose, mannitol, lactose, sucrose, raffinose) and cooled to $0^{\circ}C$ for 30 min. Sperm membrane integrity, motility and acrosome integrity were assayed after rewarming at 37$^{\circ}C$ for 5 min. Sperm motility and membrane integrity abruptly decreased with decreasing temperature but acrosome integrity gradually decreased (P<0.05). Sperm motility was more sensitive to cold shock than membrane integrity and acrosome integrity. Spermatozoa cooled to $0^{\circ}C$ were more damaged than those at 4$^{\circ}C$. Sperm motility was not different among exposed times at both. 0 and 4$^{\circ}C$. However, membrane integrity of spermatozoa exposed for 30 min at both 0 and 4$^{\circ}C$ was significantly lower (P<0.05). Spermatozoa diluted in 0.33 M fructose or galactose showed lower motility and higher morphological abnormality with coiled tail at $0^{\circ}C$. These sperm characteristics were strongly related. These results indicate that dog epididymal spermatozoa are relatively sensitive to rapid cooling and higher morphological abnormality at $0^{\circ}C$ was shown in spermatozoa diluted in fructose and galactose.

Metabolism and Pharmacokinetics of Albendazole in Korean Native Cattle (한우에서 Albendazole의 대사 및 약물동태학)

  • Yun, Hyo-in;Park, Byung-Kwon;Park, Kyoung-hwan;Lim, Jong-hwan;Hwang, Youn-hwan
    • Journal of Veterinary Clinics
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    • v.18 no.3
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    • pp.195-200
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    • 2001
  • Metabolism and phamacokinetics of albendazole have been studied in Korean native cattle after oral administration of 5 mg/kg of albendazole. As ABZ is known to be rapidly biotransformed to many metabolites in most animal species, it is very imperative to establish the analytical conditions for its metabolites. LC/MS methods for ABZSO and ABZS $O_2$met every requirement enough to study the metabolism of pharmacokinetics of albendazole in Korean native cattle. The parent drug (ABZ) was only measured at first two time points of 0.5 h and 1h, whereas two metabolites were consistently formed between 0.5 h to 48-72 h post-treatment. Formation kinetics for ABZSO and ABZS $O_2$were similar. Time to peak concentration (Tmax) of ABZ-SO appeared at 12h post-treatment of ABZ, faster than that of ABZS $O_2$at 24h. Cmax of ABZS $O_2$(1.05$\pm$0.05 ug/ml) was 1.09 times higher than that of ABZSO (0.96$\pm$0.15). Elimination half-life of ABZS $O_2$(4.2 h) was much shorter than ABZS $O_2$(7.0h) (p<0.005). ABZSO was detected until 48h post-administration but ABZS $O_2$was measurable even at 72h post-dosing. AU $C_{0longrightarrow{\infty}}$ of ABZSO was smaller than that of ABZS $O_2$. Regimen of ABZ is advised to take into consideration is metabolite profiles, especially that of ABZSO, an active metabolite.

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Residual Characteristics of Bistrifluron and Chlorantraniliprole in Strawberry (Fragaria ananassa Duch.) for Establishing Pre-Harvest Residue Limit (생산단계 잔류허용기준 설정을 위한 딸기 중 bistrifluron과 chlorantraniliprole의 잔류 특성 연구)

  • Lee, Jae Won;Kim, Ji Yoon;Kim, Hee gon;Hur, Kyung Jin;Kwon, Chan Hyeok;Hur, Jang Hyun
    • Korean Journal of Environmental Agriculture
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    • v.36 no.1
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    • pp.57-62
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    • 2017
  • BACKGROUND: Pesticide residue analysis is essentially required for safety evaluation of agricultural products. Bistrifluron and chlorantraniliprole have been currently considered as potentials to deeply evaluate their residues in agricultural products because they are frequently found in strawberry. This work was performed to investigate the residual patterns of bistrifluron and chlorantraniliprole in strawberry after harvest. METHODS AND RESULTS: Strawberry was treated with bistrifluron and chlorantraniliprole 0, 1, 2, 3, 5, 7 and 10 days before harvest under greenhouse conditions. The strawberry samples were subjected to solvent and solid phase extractions followed by LC-MS/MS analysis. There covery percentages of bistrifluron and chlorantraniliprole for tified in the control samples ranged from approximately 82 to 103% with the method limit of 0.005 mg/kg. The concentrations of bistrifluron and chlorantraniliprole in strawberry samples decreased significantly in 10 days after treatment, giving the safety levels of 0.04 to 0.06 mg/kg at 10 days after application, as considered maximum residue limit. The half-lives of bistrifluron and chlorantraniliprole based on first order kinetics were determined to 6.3 days and 6.4 days, respectively. CONCLUSION: Bistrifluron and chlorantraniliprole are suggested to use in strawberry 10 days before harvest to reach residual safety levels.

Development of a predictive model describing the growth of Staphylococcus aureus in processed meat product galbitang (식육추출가공품 중 갈비탕에서의 Staphylococcus aureus 성장예측모델 개발)

  • Son, Na-Ry;Kim, An-Na;Choi, Won-Seok;Yoon, Sang-Hyun;Suh, Soo-Hwan;Joo, In-Sun;Kim, Soon-Han;Kwak, Hyo-Sun;Cho, Joon-Il
    • Korean Journal of Food Science and Technology
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    • v.49 no.3
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    • pp.274-278
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    • 2017
  • In this study, predictive mathematical models were developed to estimate the kinetics of Staphylococcus aureus growth in processed meat product galbitang. Processed meat product galbitang was inoculated with 0.1 mL of S. aureus culture and stored at 4, 10, 20, $37^{\circ}C$. The ${\mu}_{max}$ (maximum specific growth rate) and LPD (lag phase duration) values were calculated. The primary model was used to develop a response surface secondary model. The growth parameters were analyzed using the square root model as a function of storage temperature. The developed model was confirmed by calculating RMSE (Root Mean Square Error) values as statistic parameters. The LPD decreased, but ${\mu}_{max}$ increased with an increase in the storage temperature. At 4, 10, 20 and $37^{\circ}C$, $R^2$ was 0.99, 0.98, 0.99 and 0.99, respectively; RMSE was 0.39. The developed predictive growth model can be used to predict the risk of S. aureus contamination in processed meat product galbitang; hence, it has potential as an input model for the risk assessment.

Development of a Predictive Model Describing the Growth of Staphylococcus aureus in Pyeonyuk marketed (시중 유통판매 중인 편육에서의 Staphylococcus aureus 성장예측모델 개발)

  • Kim, An-Na;Cho, Joon-Il;Son, Na-Ry;Choi, Won-Seok;Yoon, Sang-Hyun;Suh, Soo-Hwan;Kwak, Hyo-Sun;Joo, In-Sun
    • Journal of Food Hygiene and Safety
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    • v.32 no.3
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    • pp.206-210
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    • 2017
  • This study was performed to develope mathematical models for predicting growth kinetics of Staphylococcus aureus in the processed meat product, pyeonyuk. Growth patterns of S. aureus in pyeonyuk were determined at the storage temperatures of 4, 10, 20, and $37^{\circ}C$ respectively. The number of S. aureus in pyeonyuk increased at all the storage temperatures. The maximum specific growth rate (${\mu}_{max}$) and lag phase duration (LPD) values were calculated by Baranyi model. The ${\mu}_{max}$ values went up, while the LPD values decreased as the storage temperature increased from $4^{\circ}C$ to $37^{\circ}C$. Square root model and polynomial model were used to develop the secondary models for ${\mu}_{max}$ and LPD, respectively. Root Mean Square Error (RMSE) was used to evaluate the developed model and the fitness was determind to be 0.42. Therefore the developed predictive model was useful to predict the growth of S. aureus in pyeonyuk and it will help to prevent food-born disease by expanding for microbial sanitary management guide.

A Biomechanical Analysis of Judo's Kuzushi(balance-breaking) Motion (유도 팔방기울이기 동작의 생체역학적 특성 분석)

  • Kim, Sung-Sup;Kim, Eui-Hwan;Kim, Tae-Whan
    • Korean Journal of Sport Biomechanics
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    • v.17 no.2
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    • pp.207-216
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    • 2007
  • The purpose of this study was to biomechanical analysis Judo's Kuzushi throwing motion in order to increase the effectiveness of Nage-waja(throwing technique). The Tori was a Judo player with 18 years experience(4th degree) while the Uke was a player with 2 years experience(1st degree). The kinematic data was captured using the Vicon motion system (7 cameras) and the kinetics were recorded by force plates(2 AMTI). The following were the results; While leaning to the front the subject's trunk's angle was $14.5^{\circ}$, the lower limbs angle was $23.8^{\circ}$, knee angle was $179.6^{\circ}$ and the vertical reaction of the left leg was 325.42N(BW 0.34) and the right leg was 233.7N(BW 0.47). While leaning back the subject's trunk's angle was $11.3^{\circ}$, the lower limbs angle was $4.1^{\circ}$, knee angle was $1761^{\circ}$ and the vertical reaction of the left leg was 299.53N(BW 0.43) and the right leg was 441.7N(BW 0.64). While leaning to the left the subject's trunk's angle was $30.8^{\circ}$, the lower limbs angle was $2.7^{\circ}$, knee angle was $175.2^{\circ}$ and the vertical reaction of the left leg was 711N(BW 1.03) and the right leg was 9.2N(BW 0.01). While leaning to the right the subject's trunk's angle was $36.5^{\circ}$, the lower limbs angle was $10.4^{\circ}$, knee angle was $175.2^{\circ}$ and the vertical reaction of the left leg was 13.2N(BW 0.02) and the right leg was 694.7N(BW 1.01). While leaning to the left front corner the subject's trunk's angle was $19.8^{\circ}$ (front) and $15.1^{\circ}$ (left), the lower limbs angle was $17.8^{\circ}$ (front) and $2.4^{\circ}$ (left), knee angle was $177.8^{\circ}$ (front) and $173.9^{\circ}$(left), and the vertical reaction of the left leg was 547.4N(BW 0.8) and the right leg was 117.8N(BW 0.17). While leaning to the right front corner the subject's trunk's angle was $15.4^{\circ}$ (front) and $17.7^{\circ}$ (right), the lower limbs angle was $21.1^{\circ}$, (front) and $5.7^{\circ}$ (right), knee angle was $175.5^{\circ}$ (front) and $178.9^{\circ}$(right), and the vertical reaction of the left leg was 53N(BW 0.08) and the right leg was 622.4N(BW 09). While leaning to the left rear corner the subject's trunk's angle was $9.2^{\circ}$ (back) and $13.8^{\circ}$ (left), the lower limbs angle was $2^{\circ}$, (back) and $5.7^{\circ}$ (left), knee angle was $175.5^{\circ}$ (back) and $172.8^{\circ}$(left), and the vertical reaction of the left leg was 698.2N(BW 1.02) and the right leg was 49.6N(BW 0.07). While leaning to the right rear corner the subject's trunk's angle was $8.9^{\circ}$ (back) and $19.6^{\circ}$ (right), the lower limbs angle was ${0.6^{\circ}}_"$ (back) and $3.1^{\circ}$ (right), knee angle was $174.6^{\circ}$ (back) and $175.6^{\circ}$(right), and the vertical reaction of the left leg was 7.2N(BW 0.01) and the right leg was 749.4N(BW 1.09). It was observed that during the Judo motion Kuzushii the range of the COM varied from $26.5{\sim}39.9cm$. It was concluded that the upper body leaned further than the lower body as there was knee extension. There was high left leg reaction forces while leaning to the left and likewise for the right side. It was therefore deduced that the Kuzushi was a more effective throwing technique for the left side.