• Title/Summary/Keyword: enzyme inhibitors

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Angiotensin I-Converting Enzyme Inhibitor Activity on Egg Albumen Fermentation

  • Nahariah, N.;Legowo, A.M.;Abustam, E.;Hintono, A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.6
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    • pp.855-861
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    • 2015
  • Lactobacillus plantarum is used for fermentation of fish products, meat and milk. However, the utilization of these bacteria in egg processing has not been done. This study was designed to evaluate the potential of fermented egg albumen as a functional food that is rich in angiotensin I-converting enzyme inhibitors activity (ACE-inhibitor activity) and is antihypertensive. A completely randomized design was used in this study with six durations of fermentation (6, 12, 18, 24, 30, and 36 h) as treatments. Six hundred eggs obtained from the same chicken farm were used in the experiment as sources of egg albumen. Bacteria L. plantarum FNCC 0027 used in the fermentation was isolated from cow's milk. The parameters measured were the total bacteria, dissolved protein, pH, total acid and the activity of ACE-inhibitors. The results showed that there were significant effects of fermentation time on the parameters tested. Total bacteria increased significantly during fermentation for 6, 12, 18, and 24 h and then decreased with the increasing time of fermentation to 30 and 36 h. Soluble protein increased significantly during fermentation to 18 h and then subsequently decreased during of fermentation to 24, 30, and 36 h. The pH value decreased markedly during fermentation. The activities of ACE-inhibitor in fermented egg albumen increased during fermentation to 18 h and then decreased with the increasing of the duration of fermentation to 24, 30, and 36 h. The egg albumen which was fermented for 18 h resulted in a functional food that was rich in ACE-inhibitor activity.

Selective Inhibition of Bicyclic Tetrapeptide Histone Deacetylase Inhibitor on HDAC4 and K562 Leukemia Cell

  • Li, Xiao-Hui;Huang, Mei-Ling;Wang, Shi-Miao;Wang, Qing
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7095-7100
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    • 2013
  • Histone deacetylase (HDAC) inhibitors of cyclic peptide have been proved to be the most complex but the most stable and relative efficient inhibitors because of their large cap region. In this paper, a series of studies were carried out to evaluate the efficacy of synthetic bicyclic tetrapeptide inhibitors 1-5 containing hydroxamic acid referring molecular docking, anti-proliferation, morphology and apoptosis. Docking analysis, together with enzyme inhibitory results, verified the selective capability of inhibitor 4 to HDAC4, which might closely related to haematological tumorigenesis, with Phe227, Asp115, Pro32, His198 and Ser114 participating into hydrophobic interactions and Van der Waals force which was familiar with former study. Moreover, inhibitor 4 inhibited K562 cell line at the $IC_{50}$ value of 1.22 ${\mu}M$ which was 51-67 times more efficient than that for U937 and HL60 cell lines. Inhibitor 4 exhibited the cell cycle-arrested capability to leukemia at S phase or G2/M phase as well as apoptosis-induced ability in different degrees. Finally, we considered that bicyclic tetrapeptide inhibitors were promising inhibitors used in cancer treatment and inhibitor 4 could prevent K562 cell line well from proliferation, arrest cell cycle and induce K562 towards apoptosis to achieve the goals of reversing cancer cells which could become a potential leukemia therapeutic agent in the future.

HQSAR Study of Microsomal Prostaglandin E2 Synthase (mPGES-1) Inhibitors

  • San Juan, Amor A.;Cho, Seung-Joo;Cho, Hoon
    • Bulletin of the Korean Chemical Society
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    • v.27 no.10
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    • pp.1531-1536
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    • 2006
  • Microsomal prostaglandin $E_2$ synthase (mPGES-1) is an enzyme that is associated with inflammation, pain, fever and cancer. Hologram quantitative structure activity relationship (HQSAR) was conducted on the series of MK-886 compounds acting as mPGES-1 inhibitors. A training set with 24 compounds was used to establish the HQSAR model. The best model was chosen based on the cross-validated correlation coefficient ($q^2$=0.884) and the correlation coefficient($r^2$=0.976). The model was utilized to predict the activity of the eight-test set of compounds giving the predictive $r^2$ value of 0.845. The descriptors of the model are based on fragment distinction (atoms, bond and connectivity) and fragment size (2-5 atoms). The atomic contribution maps generated from HQSAR were useful in identifying the important structural features responsible for the inhibitory activity of MK-886 inhibitors. Based on the generated model, the presence of hydrophobic biphenyl group seems to enhance inhibition of mPGES-1 that is in agreement with the previous experiments. In addition, it seems important for a halogen to be substituted to the biphenyl ring and for an acyl group to be attached to the indole moiety for enhanced activity.

Role of NADPH Oxidase in the Mechanism of Arachidonic Acid-induced Apoptosis in HepG2 Human Hepatoblastoma Cells (HepG2 간암세포에서 아라키돈산에 의한 세포사멸기전에 미치는 NADPH 산화효소의 역할)

  • Nam, Jyung-Won;Lee, Yong-Soo
    • YAKHAK HOEJI
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    • v.56 no.2
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    • pp.80-85
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    • 2012
  • Previously, we have reported that arachidonic acid (AA) appears to be involved in the induction of apoptosis in HepG2 human hepatoblastoma cells. In this study we investigated the possible role of the NADPH oxidase, a membranebound enzyme generating reactive oxygen species (ROS), in the mechanism of AA-induced apoptosis in HepG2 cells. Apoptotic cell death induced by AA was significantly suppressed by various inhibitors of the NADPH oxidase, diphenylene iodonium (DPI), apocynin (Apo) and neopterine (NP). In addition, these inhibitors of the NADPH oxidase completely blunted the AA-induced ROS elevation. Next, we investigated the implication of metabolic pathway of AA in these AA actions. Both apoptosis and ROS production induced by AA were not significantly altered by treatment with indomethacin (Indo) or nordihydroguaiaretic acid (NDGA), selective inhibitors of cyclooxygenase (COX) and lipoxygenase (LOX), respectively, suggesting that AA metabolites produced by COX or LOX may not have an essential role in the AA-induced apoptosis and ROS generation. Collectively, these results suggest that the NADPH oxidase may be a key player in the mechanism of AA-induced apoptosis in HepG2 cells. These results further suggest that NADPH oxidase may be a good target for the management of human hepatomas.

3D-QSAR Studies on 2-(indol-5-yl)thiazole Derivatives as Xanthine Oxidase (XO) Inhibitors

  • Nagarajan, Santhosh Kumar;Madhavan, Thirumurthy
    • Journal of Integrative Natural Science
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    • v.8 no.4
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    • pp.258-266
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    • 2015
  • Xanthine Oxidase is an enzyme, which oxidizes hypoxanthine to xanthine, and xanthine to uric acid. It is widely distributed throughout various organs including the liver, gut, lung, kidney, heart, brain and plasma. It is involved in gout pathogenesis. In this study, we have performed Comparative Molecular Field Analysis (CoMFA) on a series of 2-(indol-5-yl) thiazole derivatives as xanthine oxidase (XO) inhibitors to identify the structural variations with their inhibitory activities. Ligand based CoMFA models were generated based on atom-by-atom matching alignment. In atom-by-atom matching, the bioactive conformation of highly active molecule 11 was generated using systematic search. Compounds were aligned using the bioactive conformation and it is used for model generation. Different CoMFA models were generated using different alignments and the best model yielded a cross-validated $q^2$ of 0.698 with five components and non-cross-validated correlation coefficient ($r^2$) of 0.992 with Fisher value as 236.431, and an estimated standard error of 0.068. The predictive ability of the best CoMFA models was found to be $r^2_{pred}$0.653. The CoMFA study revealed that the $R_3$ position of the structure is important in influencing the biological activity of the inhibitors. Electro positive groups and bulkier substituents in this position enhance the biological activity.

Receptor-oriented Pharmacophore-based in silico Screening of Human Catechol O-Methyltransferase for the Design of Antiparkinsonian Drug

  • Lee, Jee-Young;Baek, Sun-Hee;Kim, Yang-Mee
    • Bulletin of the Korean Chemical Society
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    • v.28 no.3
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    • pp.379-385
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    • 2007
  • Receptor-oriented pharmacophore-based in silico screening is a powerful tool for rapidly screening large number of compounds for interactions with a given protein. Inhibition of the enzyme catechol-Omethyltransferase (COMT) offers a novel possibility for treating Parkinson's disease. Bisubstrate inhibitors of COMT containing the adenine of S-adenosylmethionine (SAM) and a catechol moiety are a new class of potent and selective inhibitor. In the present study, we used receptor-oriented pharmacophore-based in silico screening to examine the interactions between the active site of human COMT and bisubstrate inhibitors. We generated 20 pharmacophore maps, of which 4 maps reproduced the docking model of hCOMT and a bisubstrate inhibitor. Only one of these four, pharmacophore map I, effectively described the common features of a series of bisubstrate inhibitors. Pharmacophore map I consisted of one hydrogen bond acceptor (to Mg2+), three hydrogen bond donors (to Glu199, Glu90, and Gln120), and one hydrophobic feature (an active site region surrounded by several aromatic and hydrophobic residues). This map represented the most essential pharmacophore for explaining interactions between hCOMT and a bisubstrate inhibitor. These results revealed a pharmacophore that should help in the development of new drugs for treating Parkinson's disease.

Screening and Classification of Actinomycetes Producing $\alpha$-Amylase Inhibitors and the Isolation, their Kinetic Studies of $\alpha$-Amylase Inhibitors ($\alpha$-Amylase 저해제 생산 방선균의 선별과 분류 및 $\alpha$-Amylase저해제의 분리와 Kinetics 연구)

  • 김제학;김정우;김하원;심미자;최응칠;김병각
    • Microbiology and Biotechnology Letters
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    • v.13 no.3
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    • pp.223-232
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    • 1985
  • To find microorganisms of producing $\alpha$-amylase inhibitors, actinomycetes were isolated from soil samples that were collected at different locations in Korea and screened for enzyme inhibitory activity. A strain of these microbes had a high inhibitory activity and was identified as one of the genus Streptomyces by morphological, biochemical and physiological studies according to the methods of the International Streptomyces Project (ISP). The medium used consisted of 3 % corn starch, 0.2% yeast extract and 0.8% peptone (pH 7.0). When this strain was aerobically cultured in the medium on a rotary shaker, the highest inhibitory activity was obtained after four days. This inhibitor had inhibitory activities on various $\alpha$-amylases and glucoamylase, but not on $\beta$-amylase.

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GERI-BP001 Compounds, New Inhibitors of Acyl-CoA: Cholesterol Acyltransferase from Aspergillus fumigatus F37

  • Jeong, Tae-Sook;Kim, Sung-Uk;Son, Kwang-Hee;Kwon, Byoung-Mog;Kim, Young-Kook;Bok, Song-Hae
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1995.04a
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    • pp.67-67
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    • 1995
  • Acyl-CoA:cholesterol acyltransferase (ACAT, EC 2.3.1.26) plays an important role in the control of intracellular free cholesterol content via its cholesterol esterifying activity. ACAT inhibitors are expected to be effective for treatment of atherosclerosis and hypercholesterolemia. In the course of a screening program for ACAT inhibitors from microbial sources, GERI-BP001 M, A, and B were isolated from the fermentation broth of a fungal strain. GERI-BP001 compounds were isolated from a culture broth of Aspergillus fumigatus F37 by acetone extraction, EtOAc extraction, SiO$_2$ column chromatography, and reverse phase HPLC. The structure of GERI-BP001 coumpounds were determined by $^1$H-NMR, $\^$l3/C-NMR, 2D-NMR, NOESY, and long range C-H COSY experiments. GERI-BP001 M, A, and B inhibit ACAT activity in an enzyme assay system using rat liver microsomes by 50% at concentrations of 75, 147, and 71 ${\mu}$M, respectively.

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Adenosine Kinase Inhibitor Design Based on Pharmacophore Modeling

  • Lee, Yun-O;Bharatham, Nagakumar;Bharatham, Kavitha;Lee, Keun-Woo
    • Bulletin of the Korean Chemical Society
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    • v.28 no.4
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    • pp.561-566
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    • 2007
  • Adenosine kinase (AK) is a ubiquitous intracellular enzyme, which catalyzes the phosphorylation of adenosine (ADO) to adenosine monophosphate (AMP). AK inhibitors have therapeutic potential as analgesic and antiinflammatory agents. A chemical feature based pharmacophore model has been generated from known AK inhibitors (26 training set compounds) by HypoGen module implemented in CATALYST software. The top ranked hypothesis (Hypo1) contained four features of two hydrogen-bond acceptors (HBA) and two hydrophobic aromatics (Z). Hypo1 was validated by 124 test set molecules with a correlation coefficient of 0.905 between experimental and estimated activity. It was also validated by CatScramble method. Thus, the Hypo1 was exploited for searching new lead compounds over 238,819 chemical compounds in NCI database and then the selected compounds were screened based on restriction estimated activity and Lipinski's rules to evaluate their drug-like properties. Finally we could obtain 72 new lead candidates and the two best compound structures from them were posted.

Identification of Novel Irreversible Inhibitors of UDP-N-Acetylglucosamine Enolpyruvyl Transferase (MurA) from Haemophilus influenzae

  • Han, Seong-Gu;Lee, Won-Kyu;Jin, Bong-Suk;Lee, Ki-In;Lee, Hyeong Ho;Yu, Yeon Gyu
    • Journal of Microbiology and Biotechnology
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    • v.23 no.3
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    • pp.329-334
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    • 2013
  • Uridinediphospho-N-acetylglucosamine enolpyruvyl transferase (MurA, E.C. 2.5.1.7) is an essential bacterial enzyme that catalyzes the first step of the cell wall biosynthetic pathway, which involves the transfer of an enolpyruvyl group from phosphoenolpyruvate to uridinediphospho-Nacetylglucosamine. In this study, novel inhibitors of Haemophilus influenzae MurA (Hi MurA) were identified using high-throughput screening of a chemical library from the Korea Chemical Bank. The identified compounds contain a quinoline moiety and have much lower effective inhibitory concentrations ($IC_{50}$) than fosfomycin, a wellknown inhibitor of MurA. These inhibitors appear to covalently modify the sulfhydryl group of the active site cysteine (C117), since the C117D mutant Hi MurA was not inhibited by these compounds and excess dithiothreitol abolished their inhibitory activities. The increased mass value of Hi MurA after treatment with the identified inhibitor further confirmed that the active-site cysteine residue of Hi MurA is covalently modified by the inhibitor.