• Title/Summary/Keyword: Binding parameters

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In-silico Studies of Boerhavia diffusa (Purnarnava) Phytoconstituents as ACE II Inhibitor: Strategies to Combat COVID-19 and Associated Diseases

  • Rahul Maurya;Thirupataiah Boini;Lakshminarayana Misro;Thulasi Radhakrishnan
    • Natural Product Sciences
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    • v.29 no.2
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    • pp.104-112
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    • 2023
  • COVID-19 caused a catastrophe in human health. People infected with COVID-19 also suffer from various clinical illnesses during and after the infection. The Boerhavia diffusa plant is well known for its antihypertensive activity. ACE-II inhibitors and calcium channel blockers are reported as mechanisms for the antihypertensive activity of B. diffusa phytoconstituents. Various studies have said ACE-II is the virus's binding site to attack host cells. COVID-19 treatment commonly employs a variety of synthetic antiviral and steroidal drugs. As a result, other clinical illnesses, such as hypertension and hyperglycemia, emerge as serious complications. Safe and effective drug delivery is a prime objective of the drug development process. COVID-19 is treated with various herbal treatments; however, they are not widely used due to their low potency. Many herbal plants and formulations are used to treat COVID-19 infection, in which B. diffusa is the most widely used plant. The current study relies on discovering active phytoconstituents with ACE-II inhibitory activity in the B. diffusa plant. As a result, it can be used as a treatment option for patients with COVID-19 and related diseases. Different phytoconstituents of the B. diffusa plant were selected from the reported literature. The activity of phytoconstituents against ACE-II proteins has been studied. Molecular docking and ligand-protein interaction computation tools are used in the in-silico experiment. Physicochemical, drug-likeness, water solubility, lipophilicity, and pharmacokinetic parameters are used to evaluate phytoconstituents. Liriodenine has the best drug-likeness, bioactivity, and binding score characteristics among the selected ligands. The in-silico study aims to find the therapeutic potential of B. diffusa phytoconstituents against ACE-II. Targeting ACE-II also shows an effect against SARS-CoV-2. It can serve as a rationale for designing a drug for patient infected with COVID-19 and associated diseases.

A Comparative Study on Anti-Obesity Efficacy of Cydonia oblonga Miller Fruit Extract in Diet-Induced Obesity Animal Models (식이유도 비만 동물모델에서 마르멜로추출물의 항비만 효능 비교 연구)

  • Jung Soon Hwang;Myeong Oh Hwang;Kisung Kwon;Eun Ji Kim
    • Journal of Korean Medicine for Obesity Research
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    • v.24 no.1
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    • pp.13-24
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    • 2024
  • Objectives: The objective of this study was to explore the anti-obesity effect of Cydonia oblonga Miller fruit extract (COME) and to compare its anti-obesity efficacy with Garcinia cambogia extract (GCE) in diet-induced obese mice. Methods: Five-week-old male C57BL/6 were allocated into four groups: control diet (CD), high-fat diet (HFD), HFD + 400 mg/kg body weight (BW)/day COME (H+C), or HFD + 400 mg/kg BW/day GCE (H+G) groups. COME or GCE was administered once a day by oral gavage for eight weeks. Body weight, body fat percentage, fat weight, and biochemical parameters in serum were measured. The expressions of transcription factors and their target genes in epididymal adipose tissues were analyzed by reverse transcription polymerase chain reaction. Results: COME reduced body weight, weight gain, body fat percentage, total white adipose tissue weight, adipocyte size, and serum levels of insulin and leptin in high-fat diet-induced obese C57BL/6 mice. COME suppressed the mRNA expressions of CCAAT/enhancer binding proteinα, peroxisome proliferator-activated receptorγ, sterol-regulatory element-binding protein-1c, fatty acid synthase, and adipocyte protein 2 and increased carnitine palmitoyl transferase 1 mRNA expression in epidydimal adipose tissues. The anti-obesity efficacy of COME was found to be similar to that of GCE at the same dose. However, COME more effectively decreased adipose tissue weights, epididymal adipocyte size, serum insulin and leptin compared to GCE. Conclusions: These results demonstrated that COME is not toxic and exhibits anti-obesity efficacy at a level similar to that of GCE, suggesting that COME may be applicable as an anti-obesity agent.

Contribution of Arginine 13 to the Catalytic Activity of Human Class Pi Glutathione Transferase P1-1

  • Kong, Ji-Na;Jo, Dong-Hyeon;Do, Hyun-Dong;Lee, Jin-Ju;Kong, Kwang-Hoon
    • Bulletin of the Korean Chemical Society
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    • v.31 no.9
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    • pp.2497-2502
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    • 2010
  • Arg13 is a conserved active-site residue in all known Pi class glutathione S-transferases (GSTs) and in most Alpha class GSTs. To evaluate its contribution to substrate binding and catalysis of this residue, three mutants (R13A, R13K, and R13L) were expressed in Escherichia coli and purified by GSH affinity chromatography. The substitutions of Arg13 significantly affected GSH-conjugation activity, while scarcely affecting glutathione peroxidase or steroid isomerase activities. Mutation of Arg13 into Ala largely reduced the GSH-conjugation activity by approximately 85 - 95%, whereas substitutions by Lys and Leu barely affected activity. These results suggest that, in the GSH-conjugation activity of hGST P1-1, the contribution of Arg13 toward catalytic activity is highly dependent on substrate specificities and the size of the side chain at position 13. From the kinetic parameters, introduction of larger side chains at position 13 results in stronger affinity (Leu > Lys, Arg > Ala) towards GSH. The substitutions of Arg13 with alanine and leucine significantly affected $k_{cat}$, whereas substitution with Lys was similar to that of the wild type, indicating the significance of a positively charged residue at position 13. From the plots of log ($k_{cat}/{K_m}^{CDNB}$) against pH, the $pK_a$ values of the thiol group of GSH bound in R13A, R13K, and R13L were estimated to be 1.8, 1.4, and 1.8 pK units higher than the $pK_a$ value of the wild-type enzyme, demonstrating the contribution of the Arg13 guanidinium group to the electrostatic field in the active site. From these results, we suggest that contribution of Arg13 in substrate binding is highly dependent on the nature of the electrophilic substrates, while in the catalytic mechanism, it stabilizes the GSH thiolate through hydrogen bonding.

Effects of Temperature and n-Alcohols (Propanol, Butanol, Pentanol and Hexanol) on the Micellization of Cetyltrimethylammonium Bromide (Cetyltrimethylammonium Bromide의 미셀화 현상에 미치는 온도 효과 및 n-알코올(프로판올, 부탄올, 펜탄올 및 헥산올) 효과)

  • Lee, Byeong Hwan
    • Journal of the Korean Chemical Society
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    • v.38 no.8
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    • pp.539-546
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    • 1994
  • The critical micelle concentration(CMC) and the counterion binding $constant(\beta)$ at the CMC of cetyltrimethylammonium bromide(CTAB) in a series of aqueous solutions containing medium chain-length n-alcohols(Propanol, Butanol, Pentanol and Hexanol) have been determined from the concentration dependence of electrical conductance at serveral temperature from $17^{\circ}C\;to\;41^{\circ}C.$ Thermodynamic parameters $({\Delta}G^o_m,\;{\Delta}H^o_m,\;{\Delta}S^o_m,\;and\;{\Delta}C_p)$ associated with micelle formation of CTAB have been also estimated from the temperature dependence of CMC and $\beta$ values, and the significance of these parameters and their relation to the theory of micelle formation have been considered. The results show that an enthalpy-entropy compensation effect is usually observed for the micellization of CTAB. The effects of n-alcohols on the micellar properties (CMC and $\beta$) of CTAB solutions have been also investigated. The addition of n-alcohol to the CTAB solution in a small quantity decreases the CMC value and the counterion binding constant $(\beta)$ at the CMC, but the addition of n-alcohol in an excessive quantity increases the CMC values on the conterary. These results have been explained in terms of the effect of the micelle-solubilized alcohol on the micellar surface charge density.

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Study on the Micellization of CPC/Brij 35 Mixed Surfactant Systems in Water (순수 물에서 CPC/Brij 35 혼합계면활성제의 미셀화에 대한 연구)

  • Gil, Han-Nae;Lee, Byung-Hwan
    • Journal of the Korean Chemical Society
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    • v.53 no.2
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    • pp.118-124
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    • 2009
  • The values of critical micelle concentration (CMC) and counter ion binding constants (B) in a micellar state of CPC (1-hexadecylpyridinium chloride) with Brij 35 (polyoxyethylene(23) lauryl ether) in water were determined as a function of ${\alpha}_1$ (the overall mole fraction of CPC) by the use of electric conductivity method. Various thermodynamic parameters ($X_i,\;{\gamma}_i,\;C_i,\;a_{i}^{M},\;\beta,\;and\;{\Delta}H_{mix}$) were calculated and analyzed by means of the equations derived from the non-ideal mixed micellar model. And thermodynamic parameters (${\Delta}{G^o}_m,\;{\Delta}{H^o}_m,\;and\;{\Delta}{S^o}_m$) for the micellization of CPC/Brij 35 mixtures were also calculated from the temperature dependence of the CMC values. The values of ${\Delta}{G^o}_m$ are all negative, but the values of ${\Delta}{S^o}_m$ and ${\Delta}{H^o}_m$ are positive or negative, depending on the measured temperature and ${\alpha}_1$.

Efficacy of Flaxseed Flour as Bind Enhancing Agent on the Quality of Extended Restructured Mutton Chops

  • Sharma, Heena;Sharma, Brahma Deo;Mendiratta, S.K.;Talukder, Suman;Ramasamy, Giriprasad
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.2
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    • pp.247-255
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    • 2014
  • Consumers have become very conscious about their nutrition and well being due to changes in their socio-economic lifestyle and rapid urbanization. Therefore, development of technology for production of low cost and functional meat products is urgently required. One such approach is innovative restructuring technology in which binding of meat pieces still remains the main challenge and extension of product is generally associated with poor binding and texture. Thus, the present study was envisaged as an attempt to solve this problem by the incorporation of flaxseed flour (FF) as bind enhancing agent. The FF was used at three different levels viz., 0.5%, 1%, and 1.5% to replace lean meat in pre-standardized restructured mutton chops formulation. The products were subjected to analysis for physico-chemical, sensory and textural properties. Cooking yield, moisture percentage and fat percentage increased with increase in the level of incorporation of FF, however, protein percent and pH decreased with increase in the level of incorporation. Shear force value of product incorporated with 1.5% FF was significantly higher (p<0.01) than control and product containing 0.5% FF level. Among the sensory attributes, product with 1% flaxseed flour showed significantly higher values (p<0.05) for general appearance, binding, texture and overall acceptability. Hardness showed significant increasing (p<0.01) values with increasing levels of incorporation of flaxseed flour, however all other parameters of texture profile analysis showed a decreasing trend. On the basis of sensory scores and physico-chemical properties, the optimum incorporation level of FF was adjudged as 1%. Products incorporated with optimum level of flaxseed flour (1%) were also assessed for water activity and microbiological quality during the storage period of 15 days. It was found that the extended restructured product could be safely stored under refrigeration ($4^{\circ}C{\pm}1^{\circ}C$) in low density polyethylene (LDPE) pouches for 15 days without marked deterioration in sensory and microbiological quality. Thus, it was concluded that flaxseed flour can be used as a good bind enhancing agent in extended restructured meat products at an economic cost.

Kinetics of Intracellular Adenosine Deaminase to Substrate Analogs and Inhibitors in Aspergillus oryzae (Aspergillus oryzae의 세포내 효소인 Adenosine Deaminase의 기질 유사체와 억제물질에 대한 반응속도론적 분석)

  • Choi, Hye-Seon
    • Korean Journal of Microbiology
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    • v.32 no.1
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    • pp.84-90
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    • 1994
  • Kinetic parameters of various substrates and inhibitors were measured to elucidate the binding requirements of the active site of intracellular adenosine deaminase (ADA) in Aspergillus oryzae. 3'-Deoxyadenosine was the best substrate according to the value of relative kcat/$K_m$. Purine riboside was found to be the strongest inhibitor with the $K_i$ value of $3.7{\times}10^{-5}$M. Adenine acted neither as a substrate nor as an inhibitor, suggesting the presence of ribose at N-9 of adenosine was crucial to binding. ADA also catalyzed the dechlorination of 6-chloropurine riboside, generating inosine and chloride ions. Substrate specificity of 6-chloropurine riboside was 0.86% of adenosine. Purine riboside, a competitive inhibitor of ADA, inhibit the dechlorination with similar $K_i$ value, suggesting that the same binding site was involved in deamination and dechlorination. Among the sulfhydryl group reagents, mercurials, pchloromercuribenzoate (PCMB), mersalyl acid and $HgCl_2$ inactivated the enzyme. Mersalyl acid-inactivated ADA was reactivated by thiol reagents, but PCMB-inactivated enzyme was not. When ADA was treated with the mercurial reagents, the inhibition constants and inhibition patterns were determined. Each inhibition was competitive with substrate. The $K_i$ values of these mercurial reagents were lower in 10 mM phosphate buffer than in 100 mM phosphate buffer, showing phosphate dependency.

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Studies on Physical Properties of Pork Frozen by Various High Pressure Freezing Process (초고압 동결 처리 방법에 따른 돈육의 물리적 특성에 관한 연구)

  • Ko, Se-Hee;Hong, Geun-Pyo;Park, Sung-Hee;Choi, Mi-Jung;Min, Sang-Gi
    • Food Science of Animal Resources
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    • v.26 no.4
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    • pp.464-470
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    • 2006
  • This study was carried out to investigate the effect of various high pressure freezing treatments on the physical properties of pork To compare the effect of freezing on meat quality, atmospheric freezing (AF), pressure and freezing (PF), pressure shift freezing (USF) and pressure assisted freezing (PAF) were conducted at pressure of 100 MPa. Water binding properties, shear force and colour were measured as physical properties of pork PAF showed shorter phase transition time than PSF. Although significant increase (p<0.05) in water binding properties was found only at PAF, meat frozen under hydrostatic pressure environment showed improved water binding properties. However, all high pressure freezing treatment caused significantly increased shear force (p<0.05), especially at PF treatment. In color, all high pressure freezing treatments showed significantly higher color parameters (p<0.05) than AF, whilst no significant differences among high pressure freezing treatments were found (p>0.05). Therefore the result indicated that applied hydrostatic pressure improved functional properties of pork with increasing freezing rate and PAF had more potential benefit than PSF at mild pressure range.

Lipopolysaccharide-binding protein plasma levels as a biomarker of obesity-related insulin resistance in adolescents

  • Kim, Ki Eun;Cho, Young Sun;Baek, Kyung Suk;Li, Lan;Baek, Kwang-Hyun;Kim, Jung Hyun;Kim, Ho-Seong;Sheen, Youn Ho
    • Clinical and Experimental Pediatrics
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    • v.59 no.5
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    • pp.231-238
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    • 2016
  • Purpose: Lipopolysaccharide-binding protein (LBP) is a 65-kDa acute phase protein, derived from the liver, which is present in high concentrations in plasma. Data regarding the association between circulating plasma LBP levels and obesity-related biomarkers in the pediatric population are scarce. We aimed to determine whether there was a difference in plasma LBP levels between overweight/obese and normal-weight adolescents and to assess the correlation of circulating LBP levels with anthropometric measures and obesity-related biomarkers, including insulin resistance, liver enzyme levels, and lipid profiles. Methods: The study included 87 adolescents aged 12-13 years; 44 were overweight/obese and 43 were of normal-weight. We assessed anthropometric and laboratory measures, including body mass index (BMI), blood pressure, insulin resistance, liver enzyme levels, and lipid profiles. Plasma LBP levels were measured using an enzyme-linked immunosorbent assay. Results: The mean age of the participants was $12.9{\pm}0.3$ years. Circulating plasma LBP levels were significantly increased in overweight/obese participants compared with those in normal-weight participants ($7.8{\pm}1.9{\mu}g/mL$ vs. $6.0{\pm}1.6{\mu}g/mL$, P<0.001). LBP levels were significantly and positively associated with BMI, systolic blood pressure, aspartate aminotransferase, alanine aminotransferase, total cholesterol, low density lipoprotein-cholesterol, fasting glucose and insulin, and insulin resistance as indicated by the homeostatic model assessment of insulin resistance (HOMA-IR) (all P<0.05). In multivariate linear regression analysis, BMI and HOMA-IR were independently and positively associated with plasma LBP levels. Conclusion: LBP is an inflammatory biomarker associated with BMI and obesity-related insulin resistance in adolescents. The positive correlation between these parameters suggests a potentially relevant pathophysiological mechanism linking LBP to obesity-related insulin resistance in adolescents.

Studies on the Disposition of Brazilin in rats (천연색소 Brazilin의 체내동태에 관한 연구)

  • 문창규;황지원;김지영;원현순;윤여표
    • Journal of Food Hygiene and Safety
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    • v.5 no.1
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    • pp.7-12
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    • 1990
  • The disposition of Brazilin including plasma concentration-time profiles, excretions via urine and bile, and plasma protein binding was investigated after intravenous or oral administration of radio labeled Brazilin ($^3H-Brazilin$) to male Wistar rats. The main pharmac:okinetic parameters were as follows; $t\;_{ 1/2}$, 13.71 hr; AUC, $53.38\;\mu\textrm{g}{\cdot}hr/ml$; AUMC, $1013.4I\;\mu\textrm{g}{\cdot}hr^2/ml$, MRT, 18.95 hr; Vss, 17778 mllkg and CL, 936.77 ml/hr.kg. The 2nd peak was found in the plasma concentration-time profiles indicating potential enterohepatic circulation. The enterohepatic circulation was supported by the bile excretion. After oral administration, about 64.4 % of administered radioactivity was excreted into the bile within 10 hours and its excretion rate reached maximum at 3 hours after administration. The Vss was extremely high, 17.8 l/kg indicating distribution of brazilin in most organs (tissues) with high concentration of brazilin in some organs. Brazilin was distributed into most of organs (spleen, adrenal, pancreas, kidney, thymus, lung, heart, liver, prostate, epididymus, testis, fat, muscle and done) except brain. High concentration of Brazilin was detected especially in liver, kidney, epididymus and testis. Approximately, 62.9% and 44.1% of the dose was excreted for intravenous and oral administration, respectively. About 80% of the dose eventually excreted into urine was excreted within 24 hr after dosing. Plasma protein binding of brazilin resulted in $40\;{\pm}\;4%$ by ultrafiltration method.

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