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Enzyme inhibitor

Johannes A Eble
The dissociation constant describes the interaction between two partners in the binding equilibrium and is a measure of their affinity. It is a crucial parameter to compare different ligands, e.g., competitive inhibitors, protein isoforms and mutants, for their binding strength to a binding partner. Dissociation constants are determined by plotting concentrations of bound versus free ligand as binding curves. In contrast, titration curves, in which a signal that is proportional to the concentration of bound ligand is plotted against the total concentration of added ligand, are much easier to record...
February 15, 2018: Journal of Visualized Experiments: JoVE
Ryan J Mailloux, Adrian Young, Marisa O'Brien, Robert Morris Gill
It has been reported that mitochondria can contain up to 12 enzymatic sources of reactive oxygen species (ROS). A majority of these sites include flavin-dependent respiratory complexes and dehydrogenases that produce a mixture of superoxide (O2●- ) and hydrogen peroxide (H2O2). Accurate quantification of the ROS-producing potential of individual sites in isolated mitochondria can be challenging due to the presence of antioxidant defense systems and side reactions that also form O2●- /H2O2. Use of nonspecific inhibitors that can disrupt mitochondrial bioenergetics can also compromise measurements by altering ROS release from other sites of production...
February 24, 2018: Journal of Visualized Experiments: JoVE
Xiao-Yan Huang, Yu-Guang Wang, Yi Wang, Yue Gao
This study aimed to investigate the effect and mechanism of ophiopogonin D (OP-D) on Ang Ⅱ-induced HUVECs apoptosis, in order to provide a reliable basis for the safety and efficacy of traditional Chinese medicines. The effect of Ang Ⅱ on survival and total proteins content of HUVECs were measured by MTT and Western blotting. The effect of OP-D on Ang Ⅱ-induced lactate dehydrogenase (LDH) release rate in HUVECs was measured by enzyme standard instrument. The effects of OP-D and 11,12-EET on phosphorylation of JNK/c-Jun induced by Ang Ⅱ were measured by Western blot and RT-PCR with the help of JNK specific inhibitor SP600125 and CYP450 isozymes selective inhibitor 6-(2-propargyloxyphenyl) hexanoic acid (PPOH)...
January 2018: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
Sanna Rauhamäki, Pekka A Postila, Sanna Niinivehmas, Sami Kortet, Emmi Schildt, Mira Pasanen, Elangovan Manivannan, Mira Ahinko, Pasi Koskimies, Niina Nyberg, Pasi Huuskonen, Elina Multamäki, Markku Pasanen, Risto O Juvonen, Hannu Raunio, Juhani Huuskonen, Olli T Pentikäinen
Monoamine oxidase B (MAO-B) catalyzes deamination of monoamines such as neurotransmitters dopamine and norepinephrine. Accordingly, small-molecule MAO-B inhibitors potentially alleviate the symptoms of dopamine-linked neuropathologies such as depression or Parkinson's disease. Coumarin with a functionalized 3-phenyl ring system is a promising scaffold for building potent MAO-B inhibitors. Here, a vast set of 3-phenylcoumarin derivatives was designed using virtual combinatorial chemistry or rationally de novo and synthesized using microwave chemistry...
2018: Frontiers in Chemistry
Hiren Vallabh, Bethani Hahn, Cara Bryan, Jeffery Hogg, Justin T Kupec
Intestinal angioedema is a rare side effect of angiotensin-converting enzyme inhibitors. We present a 41-year-old woman with sporadic right lower quadrant abdominal pain and diarrhea with multiple computed tomography scans demonstrating enteritis. Suspicion turned to angiotensin-converting enzyme inhibitor use as the cause for the patient's illness after an extensive negative evaluation including labs, stool studies, endoscopies, and capsule endoscopy. Weeks after stopping the medication, the patient's symptoms improved and repeat computed tomography showed a resolution of the previously seen findings of enteritis...
February 2018: Radiology Case Reports
Fernando Francisco Borges Resende, Simoneide Souza Titze-de-Almeida, Ricardo Titze-de-Almeida
Astrocytic tumors, including astrocytomas and glioblastomas, are the most common type of primary brain tumors. Treatment for glioblastomas includes radiotherapy, chemotherapy with temozolomide (TMZ) and surgical ablation. Despite certain therapeutic advances, the survival time of patients is no longer than 12-14 months. Cancer cells overexpress the neuronal isoform of nitric oxide synthase (nNOS). In the present study, it was examined whether the nNOS enzyme serves a role in the damage of astrocytoma (U251MG and U138MG) and glioblastoma (U87MG) cells caused by TMZ...
April 2018: Oncology Letters
Jennifer Luk, Yong Lu, Amanda Ackermann, Xiaoxue Peng, Diane Bogdan, Michelino Puopolo, David E Komatsu, Simon Tong, Iwao Ojima, Mario J Rebecchi, Martin Kaczocha
Background: Metabolism of the endocannabinoid 2-arachidonoylglycerol (2-AG) yields arachidonic acid (AA), the precursor to proalgesic eicosanoids including prostaglandin E2 (PGE2 ). Diacylglycerol lipase β (DAGLβ) is an enzyme that synthesizes 2-AG and its inhibition reduces eicosanoid levels and produces antinociceptive effects in models of inflammatory pain. Here we test whether inhibition of DAGLβ produces antinociceptive effects in a model of postoperative pain. Methods: Rats were administered the selective DAGLβ inhibitor KT109 or vehicle and underwent plantar incision...
2018: Journal of Pain Research
Monica G Ferrini, Eduardo Garcia, Andrea Abraham, Jorge N Artaza, Sabine Nguyen, Jacob Rajfer
INTRODUCTION: COMP-4 is a natural compound-based dietary supplement consisting of the combination of ginger, Paullinia cupana, muira puama and l-citrulline, which when given long-term has been shown in the aged rat to a) upregulate iNOS in the penile smooth muscle cells (SMC), b) reverse the corporal SMC apoptosis and fibrosis associated with corporal veno-occlusive dysfunction (CVOD), and c) improve resulting erectile function. To elucidate the mechanism of how COMP-4 and its individual components modulate the iNOS-cGMP pathway, an in vitro study was conducted using a rat corporal primary SMC culture to determine its effect on NOS, soluble guanylate cyclase (sGC), cGMP and the phosphodiesterase 5 enzyme (PDE5)...
March 15, 2018: Nitric Oxide: Biology and Chemistry
Connor M Pettem, Jennifer M Briens, David M Janz, Lynn P Weber
Selenium (Se) is considered an essential trace element, involved in important physiological and metabolic functions for all vertebrate species. Fish require dietary concentrations of 0.1-0.5 μg Se/g dry mass (d.m.) to maintain normal physiological and selenoprotein function, however concentrations exceeding 3 μg/g d.m. have been shown to cause toxicity. As Se is reported to have a narrow margin between essentiality and toxicity, there is growing concern surrounding the adverse effects of elevated Se exposure caused by anthropogenic activities...
March 8, 2018: Aquatic Toxicology
Mohamed K S El-Nagar, Hajjaj H M Abdu-Allah, Ola I A Salem, Abdel-Hamid N Kafafy, Hanan S M Farghaly
Three new series of 5-aminosalicylic acid derivatives; series I (14, 16-18), series II (19-30) and series III (31-41) were synthesized as potential dual COX-2/5-LOX inhibitors. Their chemical structures were confirmed using spectroscopic tools including IR,1 H NMR,13 C NMR, mass spectroscopy and elemental analyses. The anti-inflammatory activity for all target compounds was evaluated in vivo using carrageenan-induced paw edema. Compound 36 showed the highest anti-inflammatory activity (114.12%) relative to reference drug indomethacin at 4 h interval...
March 6, 2018: Bioorganic Chemistry
Mohamed A Abdelgawad, Madlen B Labib, Waleed A M Ali, Gehan Kamel, Amany A Azouz, El-Shaymaa El-Nahass
A series of newly synthesized 4-aryl-hydrazonopyrazolones were designed and their structures were confirmed by spectral and elemental analyses. All synthesized compounds were evaluated for their in vitro COXs, 5-LOX inhibition, in vivo analgesic and anti-inflammatory activities. Compounds 5d, 5f and 5i were found to be the most potent COX-2/5-LOX inhibitors with superior COX-2 selectivity index values (SI = 5.29-5.69) to reference standard celecoxib (SI = 3.52). Four compounds; 5b, 5c, 5d and 5f showed excellent anti-inflammatory activity (% edema inhibition = 72...
March 8, 2018: Bioorganic Chemistry
Hironao Nakayama, Tomohisa Sakaue, Masashi Maekawa, Ayako Fujisaki, Shigeki Higashiyama
A disintegrin and metalloproteinase (ADAM) family are crucial enzymes for ectodomain shedding of multiple substrates and are involved in diverse biologic and pathologic processes. However, the molecular mechanism underlying substrate selectivity of ADAMs is poorly understood. In this study, we observed that disruption of actin polymerization by pharmacological inhibitors, latrunculin A (LatA) and cytochalasin D (CyD), induced ectodomain shedding of epidermal growth factor (EGF) family ligands. Induced shedding activity by LatA or CyD was suppressed by a metalloprotease inhibitor KB-R7785, indicating that ADAMs-mediated shedding is tightly controlled by actin cytoskeleton...
March 14, 2018: Biochemical and Biophysical Research Communications
Adriana Ferreira Lopes Vilela, Cláudia Seidl, Juliana Maria de Lima, Carmen Lúcia Cardoso
Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are key cholinesterase enzymes responsible for the hydrolysis of acetylcholine into choline and acetic acid, an essential process for the restoration of the cholinergic neuron. The loss of cholinergic function in the central nervous system contributes to the cognitive decline associated with advanced age and Alzheimer's disease (AD). Inhibitions assays represent a significant role in the drug discovery process. Herein, we describe an improved label free method to screen and characterize new BChE ligands...
March 14, 2018: Analytical Biochemistry
Kira Mergemeier, Matthias Lehr
Recently, we have described an HPLC-UV assay for the evaluation of inhibitors of plasma amine oxidase (PAO) using 6-(5-phenyl-2H-tetrazol-2-yl)hexan-1-amine (4) as a new type of substrate. Now we studied, whether this compound or homologues of it can also function as substrate for related amine oxidases, namely diamine oxidase (DAO), monoamine oxidase A (MAO A) and monoamine oxidase B (MAO B). Among these substances, 4 was converted by DAO with the highest rate. The best substrate for MAO A and B was 4-(5-phenyl-2H-tetrazol-2-yl)butan-1-amine (2)...
March 15, 2018: Analytical Biochemistry
Hidenobu Murafuji, Hiroki Sakai, Megumi Goto, Yoshiaki Oyama, Seiichi Imajo, Hajime Sugawara, Toshiyuki Tomoo, Tsuyoshi Muto
A novel series of 1,3,6-trisubstituted 1,4-diazepan-7-ones were investigated as human kallikrein 7 (KLK7, stratum corneum chymotryptic enzyme) inhibitors. Based on the X-ray co-crystal structure of compound 1 bound to human KLK7, the derivatives of this scaffold were designed, synthesized, and evaluated. Through structure-activity relationship studies focused on the side chain located in the prime site region of the enzyme, representative compounds 15, 33a, and 35a were identified as highly potent and selective inhibitors of human KLK7...
March 3, 2018: Bioorganic & Medicinal Chemistry Letters
B Tate Cutshall, Benjamin T Duhart, Jagannath Saikumar, Michael Samarin, Lydia Hutchison, Joanna Q Hudson
BACKGROUND: Treatment of heart failure with reduced ejection fraction (HFrEF) requires guideline-directed medication therapy (GDMT) consisting of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker in combination with an indicated beta-blocker. There is concern that end-stage renal disease (ESRD) patients are not being prescribed GDMT. The study aim was to determine whether outcomes differ for patients with HFrEF and ESRD receiving GDMT compared to those not receiving GDMT...
March 2018: American Journal of the Medical Sciences
Valeria La Pietra, Stefania Sartini, Lorenzo Botta, Alessandro Antonelli, Silvia Martina Ferrari, Poupak Fallahi, Alessio Moriconi, Vito Coviello, Luca Quattrini, Yi-Yu Ke, Hsieh Hsing-Pang, Federico Da Settimo, Ettore Novellino, Concettina La Motta, Luciana Marinelli
It is now known that "gain of function" mutations of RET (REarranged during Transfection) kinase are specific and key oncogenic events in the onset of thyroid gland cancers such as the Medullary Thyroid Carcinoma (MTC). Although a number of RET inhibitors exist and are capable of inhibiting RET variants, in which mutations are outside the enzyme active site, the majority becomes dramatically ineffective when mutations are within the protein active site (V804L and V804M). Pursuing a receptor-based virtual screening against the kinase domain of RET, we found that compound 5 is able to inhibit efficiently both wild type and V804L mutant RET...
March 2, 2018: European Journal of Medicinal Chemistry
Sixtine Gilliot, Igor Sibon, Jean-Louis Mas, Thierry Moulin, Yannick Béjot, Charlotte Cordonnier, Maurice Giroud, Pascal Odou, Régis Bordet, Denis Vivien, Didier Leys
BACKGROUND: Many patients who receive intravenous (i.v.) recombinant tissue-plasminogen activator (rt-PA) for acute cerebral ischemia were under angiotensin-converting enzyme inhibitors (ACE-Is) or angiotensin receptor blockers (ARBs) at stroke onset. ACE-Is and ARBs have neuroprotective properties in animal models. OBJECTIVE: To evaluate whether the 3-month outcome of patients treated with i.v. rt-PA for cerebral ischemia was influenced by on-going therapy with ACE-Is or ARBs...
March 16, 2018: Journal of Neurology
Ondrej Kuda, Marie Brezinova, Jan Silhavy, Vladimir Landa, Vaclav Zidek, Chandra Dodia, Franziska Kreuchwig, Marek Vrbacky, Laurence Balas, Thierry Durand, Norbert Hübner, Aron B Fisher, Jan Kopecky, Michal Pravenec
Fatty acid esters of hydroxy fatty acids (FAHFAs) are lipid mediators with promising anti-diabetic and anti-inflammatory properties that are formed in white adipose tissue (WAT) via de novo lipogenesis, but their biosynthetic enzymes are unknown. Using a combination of lipidomics in WAT, QTL mapping and correlation analyses in rat BXH/HXB recombinant inbred strains, and response to oxidative stress in murine models, we elucidated the potential pathway of biosynthesis of several FAHFAs.Comprehensive analysis of WAT samples identified ∼160 regioisomers documenting the complexity of this lipid class...
March 16, 2018: Diabetes
Kwang Il Jung, Chul Woong Pyo, Sang-Yun Choi
Infection with influenza A virus (IAV) A/WSN/1933 (H1N1) causes oxidative stress and severe lung injury. We have demonstrated that the generation of reactive oxygen species (ROS) during IAV infection is tightly regulated by superoxide dismutase 1 (SOD1) and correlated with viral replication in alveolar epithelial cells. However, the molecular mechanism underlying SOD1 reduction during IAV infection is uncertain. Here we demonstrate that the autophagy pathway is activated by IAV infection and involved in enhanced ROS generation in the early phase of infection...
March 16, 2018: Biochemical and Biophysical Research Communications
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