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Loop diuretics decrease the renal elimination rate and increase the plasma levels of trimethylamine-N-oxide. Br J Clin Pharmacol 2018; 84:2634-2644. [PMID: 30069897 DOI: 10.1111/bcp.13728] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 06/25/2018] [Accepted: 07/23/2018] [Indexed: 12/27/2022] Open
Abstract
AIMS Trimethylamine-N-oxide (TMAO) is a novel cardiovascular risk marker. We explored the association of commonly used cardiovascular medications with TMAO levels in patients and validated the identified associations in mice. METHODS Detailed history of drug treatment was recorded in 300 patients with cardiovascular disease without diabetes in an observational, cross-sectional study. Animal study was performed in CD1 mice. RESULTS Median plasma TMAO (interquartile range) level was 2.144 (1.570-3.104) μmol l-1 . Among nine cardiovascular drug groups, the use of loop diuretics (0.510 ± 0.296 in users vs. 0.336 ± 0.272 in nonusers, P = 0.008) and mineralocorticoid receptor antagonists (0.482 ± 0.293 in users vs. 0.334 ± 0.272 in nonusers, P = 0.007) was associated with increased log-TMAO. Acute concomitant administration of furosemide or torasemide with TMAO in mice significantly influenced TMAO pharmacokinetic profile and almost doubled the plasma TMAO area under the curve. Furosemide decreased the TMAO excretion rate by 1.9-fold during the first 30 min after administration and increased TMAO concentrations in kidney, heart and liver, suggesting the interaction of furosemide and TMAO with efflux transporters. The concentrations of TMAO in blood plasma after the administration of the organic anion transporter inhibitor probenecid were not different from those of the control group, suggesting an effect not mediated by organic anion transporters. CONCLUSIONS Loop diuretics increased plasma TMAO concentration by decreasing its urinary excretion rate. Loop diuretic use should be considered a potential confounder in TMAO studies.
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Correction to 'Intramolecular hydrogen bonds in 1,4-dihydropyridine derivatives'. ROYAL SOCIETY OPEN SCIENCE 2018; 5:180990. [PMID: 30109869 PMCID: PMC6083734 DOI: 10.1098/rsos.180990] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
[This corrects the article DOI: 10.1098/rsos.180088.].
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Intramolecular hydrogen bonds in 1,4-dihydropyridine derivatives. ROYAL SOCIETY OPEN SCIENCE 2018; 5:180088. [PMID: 30110409 PMCID: PMC6030305 DOI: 10.1098/rsos.180088] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 05/02/2018] [Indexed: 05/24/2023]
Abstract
1,4-Dihydropyridine (1,4-DHP) derivatives have been synthesized and characterized by 1H, 13C, 15N nuclear magnetic resonance (NMR) spectroscopy, secondary proton/deuterium 13C isotope shifts, variable temperature 1H NMR experiments and quantum-chemical calculation. The intramolecular hydrogen bonds NH⋯O=C and CH⋯O=C in these compounds were established by NMR and quantum-chemical studies The downfield shift of the NH proton, accompanied by the upfield shift of the 15N nuclear magnetic resonance signals, the shift to the higher wavenumbers of the NH stretching vibration in the infrared spectra and the increase of the 1J(15N,1H) values may indicate the shortening of the N-H bond length upon intramolecular NH⋯O=C hydrogen bond formation.
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Study of interactions of mononucleotides with 1,4-dihydropyridine vesicles using NMR and ITC techniques. NEW J CHEM 2018. [DOI: 10.1039/c8nj00160j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The possible binding site of mononucleotides is the phosphate group with important hydrophobic interactions between the mononucleotides and the alkyl chains of DHP derivatives.
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Lunasin is a redox sensitive intrinsically disordered peptide with two transiently populated α-helical regions. Peptides 2016; 85:56-62. [PMID: 27639324 DOI: 10.1016/j.peptides.2016.09.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 09/13/2016] [Accepted: 09/14/2016] [Indexed: 10/21/2022]
Abstract
Lunasin is a 43 amino acid peptide with anti-cancer, antioxidant, anti-inflammatory and cholesterol-lowering properties. Although the mechanism of action of lunasin has been characterized to some extent, its exact three-dimensional structure as well as the function of the N-terminal sequence remains unknown. We established a novel method for the production of recombinant lunasin that allows efficient isotope labeling for NMR studies. Initial studies showed that lunasin can exist in a reduced or oxidized state with an intramolecular disulfide bond depending on solution conditions. The structure of both forms of the peptide at pH 3.5 and 6.5 was characterized by CD spectroscopy and multidimensional NMR methods. The data indicate that lunasin belongs to the class of intrinsically disordered proteins. The analysis of secondary structure propensities indicates the presence of two helical regions and an extended (beta strand) conformation at the C-terminus. We hypothesize that the transient secondary structure elements could be stabilized upon interaction with the histones H3 and H4. The newly discovered redox properties of lunasin could explain its antioxidant and anti-inflammatory activity.
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Preparation and characterization of selenopheno[2,3-b]pyridine N-oxides. MENDELEEV COMMUNICATIONS 2016. [DOI: 10.1016/j.mencom.2016.07.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Natural-Antioxidant-Inspired Benzo[b]selenophenes: Synthesis, Redox Properties, and Antiproliferative Activity. Chem Asian J 2016; 11:1929-38. [PMID: 27146245 DOI: 10.1002/asia.201600472] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/01/2016] [Indexed: 02/02/2023]
Abstract
The cyclization of arylalkynes under selenobromination conditions, combined with an acid-induced 3,2-aryl shift, was elaborated as a general synthetic pathway for the preparation of polyhydroxy-2- and -3-arylbenzo[b]selenophenes from the same starting materials. The redox properties, free-radical-scavenging ability, and cytotoxicity against malignant cell lines (MCF-7, MDA-MB-231, HepG2, and 4T1) of the synthesized compounds were explored, and the obtained results were used to consider the structure-activity relationships (SARs) in these compounds. Consequently, the structural features that were responsible for the highly potent peroxyl-radical-scavenging activity were established.
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Abstract
Recent studies have revealed strong associations between systemic trimethylamine N-oxide (TMAO) levels, atherosclerosis and cardiovascular risk. In addition, plasma L-carnitine levels in patients with high TMAO concentrations predicted an increased risk for cardiovascular disease and incident major adverse cardiac events. The aim of the present study was to investigate the relation between TMAO and L-carnitine plasma levels and diabetes. Blood plasma samples were collected from 12 and 20 weeks old db/db mice and patients undergoing percutaneous coronary intervention. Diabetic compared to non-diabetic db/L mice presented 10-fold higher TMAO, but lower L-carnitine plasma concentrations at 12 weeks of age. After 8 weeks of observation, diabetic db/db mice had significantly increased body weight, insulin resistance and TMAO concentration in comparison to non-diabetic control. In 191 patients undergoing percutaneous coronary intervention the median (interquartile range) plasma concentration of TMAO was 1.8 (1.2-2.6) µmol/L. Analysis of the samples showed a bivariate association of TMAO level with age, total cholesterol and L-carnitine. The multivariate linear regression analysis revealed that, in addition to L-carnitine as the strongest predictor of log transformed TMAO (p<0.001), the parameters of age, diabetes status and body mass index (BMI) were independently associated with increased log transformed TMAO levels (p<0.01).Our data provide evidence that age, diabetes and BMI are associated with higher TMAO levels independently of L-carnitine. These data support the hypothesis of TMAO as a cardiovascular risk marker and warrant further investigation of TMAO for diabetes research applications.
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Development of N6-methyl-2-(1,2,3-triazol-1-yl)-2′-deoxyadenosine as a novel fluorophore and its application in nucleotide synthesis. Tetrahedron Lett 2016. [DOI: 10.1016/j.tetlet.2016.02.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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10
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Fused Selenazolinium Salt Derivatives with a Se-N+Bond: Preparation and Properties. European J Org Chem 2015. [DOI: 10.1002/ejoc.201500582] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Taregting acylcarnitine content in vascular tissue to attenuate development of atherosclerosis. Atherosclerosis 2015. [DOI: 10.1016/j.atherosclerosis.2015.04.331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Cyclization of Diaryl(hetaryl)alkynes under Selenobromination Conditions: Regioselectivity and Mechanistic Studies. European J Org Chem 2015. [DOI: 10.1002/ejoc.201500431] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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13
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1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC) increases Carmofur stability and in vitro antiproliferative effect. Toxicol Rep 2015; 2:377-383. [PMID: 28962371 PMCID: PMC5598257 DOI: 10.1016/j.toxrep.2015.01.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 12/09/2014] [Accepted: 01/06/2015] [Indexed: 10/28/2022] Open
Abstract
Addition of DMPC considerably inhibits the degradation of Carmofur in neutral phosphate buffer solutions and this drug becomes less influenced by pH. Carmofur stabilization at neutral pH caused by DMPC addition for in vitro studies was characterized and monitored by 1H NMR. Antiproliferative activity studies on various tumor cell lines showed considerable increase of Carmofur ability to prevent tumor cell growth, when it is added as a mixture with DMPC. This technique opens a way for Carmofur drug delivery in neutral and basic media.
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Inhibition of L-carnitine biosynthesis and transport by methyl-γ-butyrobetaine decreases fatty acid oxidation and protects against myocardial infarction. Br J Pharmacol 2015; 172:1319-32. [PMID: 25363063 DOI: 10.1111/bph.13004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 10/21/2014] [Accepted: 10/28/2014] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND AND PURPOSE The important pathological consequences of ischaemic heart disease arise from the detrimental effects of the accumulation of long-chain acylcarnitines in the case of acute ischaemia-reperfusion. The aim of this study is to test whether decreasing the L-carnitine content represents an effective strategy to decrease accumulation of long-chain acylcarnitines and to reduce fatty acid oxidation in order to protect the heart against acute ischaemia-reperfusion injury. KEY RESULTS In this study, we used a novel compound, 4-[ethyl(dimethyl)ammonio]butanoate (Methyl-GBB), which inhibits γ-butyrobetaine dioxygenase (IC₅₀ 3 μM) and organic cation transporter 2 (OCTN2, IC₅₀ 3 μM), and, in turn, decreases levels of L-carnitine and acylcarnitines in heart tissue. Methyl-GBB reduced both mitochondrial and peroxisomal palmitate oxidation rates by 44 and 53% respectively. In isolated hearts treated with Methyl-GBB, uptake and oxidation rates of labelled palmitate were decreased by 40%, while glucose oxidation was increased twofold. Methyl-GBB (5 or 20 mg·kg(-1)) decreased the infarct size by 45-48%. In vivo pretreatment with Methyl-GBB (20 mg·kg(-1)) attenuated the infarct size by 45% and improved 24 h survival of rats by 20-30%. CONCLUSIONS AND IMPLICATIONS Reduction of L-carnitine and long-chain acylcarnitine content by the inhibition of OCTN2 represents an effective strategy to protect the heart against ischaemia-reperfusion-induced damage. Methyl-GBB treatment exerted cardioprotective effects and increased survival by limiting long-chain fatty acid oxidation and facilitating glucose metabolism.
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Abstract
L-carnitine is a very popular food supplement due to its safety profile, antioxidant-type activity and suggested effects on energy metabolism pathways. L-carnitine participates in both fatty acid transport pathways and the export of acetyl groups out of the mitochondria. However, contradictory data exist concerning the pharmacological outcomes of L-carnitine treatment in diabetes mellitus, which is a highly prevalent metabolic disease characterised by hyperglycemia and associated with severe complications, including cardiovascular disease and dyslipidemia. Recently, the L-carnitine-derived metabolites, acylcarnitines and trimethylamine-N-oxide, have been associated with increased cardio-metabolic risks. This review aims to highlight the possible risks and benefits of L-carnitine supplementation.
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Synthesis, spectroscopic and conformational analysis of 1,4-dihydroisonicotinic acid derivatives. J Mol Struct 2014. [DOI: 10.1016/j.molstruc.2014.06.044] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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18
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NMR and Quantum-Chemical Studies of Electrostatically Stabilized 1-(N,N-Substituted-aminiomethyl)spirobi[3-oxo(2,5-dioxa-1-silacyclopentan)]ates (ES-Silanates). HETEROATOM CHEMISTRY 2014. [DOI: 10.1002/hc.21203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Semisynthesis of Libiguin A and Its Analogues by Trans-Lactonization of Phragmalin. J Org Chem 2014; 79:4148-53. [DOI: 10.1021/jo500318w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Targeting Carnitine Biosynthesis: Discovery of New Inhibitors against γ-Butyrobetaine Hydroxylase. J Med Chem 2014; 57:2213-36. [DOI: 10.1021/jm401603e] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Experimental and Theoretical Studies of Bromination of Diethyl 2,4,6-Trimethyl-1,4-dihydropyridine-3,5-dicarboxylate. HETEROATOM CHEMISTRY 2014. [DOI: 10.1002/hc.21145] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Libiguins A and B: novel phragmalin limonoids isolated from Neobeguea mahafalensis causing profound enhancement of sexual activity. PLANTA MEDICA 2014; 80:306-314. [PMID: 24549927 DOI: 10.1055/s-0033-1360390] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In a screening programme directed towards the discovery of drugs that could enhance sexual activity, we found that a decoction of the root bark of Neobeguea mahafalensis displayed an extraordinarily high potency and remarkably long duration in augmenting sexual activity in male rodents. Bioassay-guided fractionation led to the isolation of two pharmacoactive constituents, which turned out to be novel 1,8,9-orthoacetate phragmalin limonoids that we named libiguins A and B, each with a C-16/30 δ-lactone ring. Chemical structures were established by the interpretation of their 1D and 2D NMR data. In vivo pharmacological tests showed that starting with a treatment from 0.004-0.4 mg/kg/day for three consecutive days, over a 3-h sampling period, these limonoids induced a long-lasting augmentation of frequency and sustainment of mounting behaviour in male rodents, with an effect lasting for up to 11 days post-treatment. Libiguin A proved to be markedly more potent than libiguin B. This report is the first of limonoids having such an effect, and the findings could lead to novel therapies for the treatment of sexual dysfunction. Moreover, the results can serve as an opening to elucidate the central physiological control of mating behaviour, which is still not well mapped out.
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Spectral and Quantum-Chemical Study of Nonequivalence of Methylene Protons in 1,4-Dihydropyridine Derivatives*. Chem Heterocycl Compd (N Y) 2014. [DOI: 10.1007/s10593-014-1414-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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15N NMR of 1,4-dihydropyridine derivatives. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2013; 51:391-396. [PMID: 23696534 DOI: 10.1002/mrc.3959] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Revised: 03/28/2013] [Accepted: 04/03/2013] [Indexed: 06/02/2023]
Abstract
In this article, we describe the characteristic (15)N and (1)HN NMR chemical shifts and (1)J((15)N-(1)H) coupling constants of various symmetrically and unsymmetrically substituted 1,4-dihydropyridine derivatives. The NMR chemical shifts and coupling constants are discussed in terms of their relationship to structural features such as character and position of the substituent in heterocycle, N-alkyl substitution, nitrogen lone pair delocalization within the conjugated system, and steric effects.
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Synthesis and biological evaluation of 2-(5-methyl-4-phenyl-2-oxopyrrolidin-1-yl)-acetamide stereoisomers as novel positive allosteric modulators of sigma-1 receptor. Bioorg Med Chem 2013; 21:2764-71. [PMID: 23582449 DOI: 10.1016/j.bmc.2013.03.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2012] [Revised: 02/21/2013] [Accepted: 03/01/2013] [Indexed: 11/29/2022]
Abstract
Novel positive allosteric modulators of sigma-1 receptor represented by 2-(5-methyl-4-phenyl-2-oxopyrrolidin-1-yl)-acetamide enantiomers were synthesised using an asymmetric Michael addition of 2-nitroprop-1-enylbenzene to diethyl malonate. Following the chromatographic separation of the methyl erythro- and threo-4-nitro-3R- and 3S-phenylpentanoate diastereoisomers, target compounds were obtained by their reductive cyclisation into 5-methyl-4-phenylpyrrolidin-2-one enantiomers and the attachment of the acetamide group to the heterocyclic nitrogen. Experiments with electrically stimulated rat vas deference contractions induced by the PRE-084, an agonist of sigma-1 receptor, showed that (4R,5S)- and (4R,5R)-2-(5-methyl-4-phenyl-2-oxopyrrolidin-1-yl)-acetamides with an R-configuration at the C-4 chiral centre in the 2-pyrrolidone ring were more effective positive allosteric modulators of sigma-1 receptor than were their optical antipodes.
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258 THE SEVERITY OF ISCHEMIA REPERFUSION DAMAGE IS DETERMINED BY THE CHANGES IN METABOLISM PATTERN OF ENERGY SUBSTRATES IN MITOCHONDRIA. BRITISH HEART JOURNAL 2013. [DOI: 10.1136/heartjnl-2013-304019.258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Validation of the CHARMM27 force field for nucleic acids using 2D nuclear overhauser effect spectroscopy. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/jbpc.2013.42008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Structural basis for 5'-end-specific recognition of single-stranded DNA by the R3H domain from human Sμbp-2. J Mol Biol 2012; 424:42-53. [PMID: 22999958 DOI: 10.1016/j.jmb.2012.09.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 09/07/2012] [Accepted: 09/12/2012] [Indexed: 10/27/2022]
Abstract
The R3H domain is a conserved sequence motif in nucleic acid binding proteins. Previously, we reported the solution structure of the R3H domain and identified a putative nucleic acid binding site composed of three conserved basic residues [Liepinsh, E., Leonchiks, A., Sharipo, A., Guignard, L. & Otting, G. (2003). Solution structure of the R3H domain from human Sμbp-2. J. Mol. Biol.326, 217-223]. Here, we determine the binding affinities of mononucleotides and dinucleotides for the R3H domain from human Sμbp-2 (Sμbp2-R3H) and map their binding sites on the protein's surface. Although the binding affinities show up to 260-fold selectivity between different nucleotides, their binding sites and conformations seem very similar. Further, we report the NMR structure of the Sμbp2-R3H in complex with deoxyguanosine 5'-monophosphate (dGMP) mimicking the 5'-end of single-stranded DNA. Pseudocontact shifts from a paramagnetic lanthanide tag attached to residue 731 in the mutant A731C confirmed that binding of dGMP brings a loop of the protein into closer proximity. The structure provides the first structural insight into single-stranded nucleic acid recognition by the R3H domain and shows that the R3H domain specifically binds the phosphorylated 5'-end through electrostatic interactions with the two conserved arginines and stacking interactions with the highly conserved histidine.
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Functionalization of 3-Chlorobenzaldehyde. SYNTHESIS-STUTTGART 2012. [DOI: 10.1055/s-0031-1289784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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04 The regulation of mitochondrial energy metabolism by L-carnitine lowering agents in ischaemia-reperfusion injury. Heart 2011. [DOI: 10.1136/heartjnl-2011-301156.4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Asymmetric Synthesis of 1,3-Diamines. II: Diastereoselective Reduction of Atropisomeric N-tert-Butanesulfinylketimines. J Org Chem 2011; 76:2635-47. [DOI: 10.1021/jo1025767] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Saturday, 17 July 2010. Cardiovasc Res 2010. [DOI: 10.1093/cvr/cvq174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Inhibition of carnitine acetyltransferase by mildronate, a regulator of energy metabolism. J Enzyme Inhib Med Chem 2010; 24:1269-75. [PMID: 19912061 DOI: 10.3109/14756360902829527] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Carnitine acetyltransferase (CrAT; EC 2.3.1.7) catalyzes the reversible transfer of acetyl groups between acetyl-coenzyme A (acetyl-CoA) and L-carnitine; it also regulates the cellular pool of CoA and the availability of activated acetyl groups. In this study, biochemical measurements, saturation transfer difference (STD) nuclear magnetic resonance (NMR) spectroscopy, and molecular docking were applied to give insights into the CrAT binding of a synthetic inhibitor, the cardioprotective drug mildronate (3-(2,2,2-trimethylhydrazinium)-propionate). The obtained results show that mildronate inhibits CrAT in a competitive manner through binding to the carnitine binding site, not the acetyl-CoA binding site. The bound conformation of mildronate closely resembles that of carnitine except for the orientation of the trimethylammonium group, which in the mildronate molecule is exposed to the solvent. The dissociation constant of the mildronate CrAT complex is approximately 0.1 mM, and the K(i) is 1.6 mM. The results suggest that the cardioprotective effect of mildronate might be partially mediated by CrAT inhibition and concomitant regulation of cellular energy metabolism pathways.
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Asymmetric Synthesis of 1,3-Diamines by Diastereoselective Reduction of Enantiopure N-tert-Butanesulfinylketimines: Unusual Directing Effects of the ortho-Substituent. J Org Chem 2010; 75:2357-68. [DOI: 10.1021/jo100173f] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Synthesis and cytotoxic activity of derivatives of the tert-butyl ester of 7Z-acetylmethylene-3-methyl-3-cephem-4-carboxylic acid. Chem Heterocycl Compd (N Y) 2009. [DOI: 10.1007/s10593-009-0254-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Separation of Selected Heptacoordinated Derivatives of Goshchava-Silanates for HPLC. J LIQ CHROMATOGR R T 2009. [DOI: 10.1080/10826070902901549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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A novel zinc-binding fold in the helicase interaction domain of the Bacillus subtilis DnaI helicase loader. Nucleic Acids Res 2009; 37:2395-404. [PMID: 19255093 PMCID: PMC2673437 DOI: 10.1093/nar/gkp092] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The helicase loader protein DnaI (the Bacillus subtilis homologue of Escherichia coli DnaC) is required to load the hexameric helicase DnaC (the B. subtilis homologue of E. coli DnaB) onto DNA at the start of replication. While the C-terminal domain of DnaI belongs to the structurally well-characterized AAA+ family of ATPases, the structure of the N-terminal domain, DnaI-N, has no homology to a known structure. Three-dimensional structure determination by nuclear magnetic resonance (NMR) spectroscopy shows that DnaI presents a novel fold containing a structurally important zinc ion. Surface plasmon resonance experiments indicate that DnaI-N is largely responsible for binding of DnaI to the hexameric helicase from B. stearothermophilus, which is a close homologue of the corresponding much less stable B. subtilis helicase.
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A new regioselective synthesis of 2-methoxymethyl-3-oxo-2,3-di-hydro-7H-thiazolo[3,2-a]pyridine-8-carboxylic acid methylamide. Chem Heterocycl Compd (N Y) 2009. [DOI: 10.1007/s10593-009-0259-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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A Novel Anti-inflammatory Compound, Artonkin-4′-O-glucoside, from the Leaves ofArtocarpus tonkinensisSuppresses Experimentally Induced Arthritis*. Scand J Immunol 2009; 69:110-8. [DOI: 10.1111/j.1365-3083.2008.02205.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Separation of Selected Derivatives of Hoszczawa-Silanates, Taking Advantage of π–π Interactions. J LIQ CHROMATOGR R T 2008. [DOI: 10.1080/10826070802388466] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Benzo[b]thiophen-3(2H)-one 1,1-dioxide—a versatile reagent in the synthesis of spiroheterocycles. Tetrahedron 2008. [DOI: 10.1016/j.tet.2008.07.112] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Synthesis of 2-(4′-R-benzylidene)-4-aza-1,3-indanediones and investigation of isomerization around the exocyclic double bond. Chem Heterocycl Compd (N Y) 2008. [DOI: 10.1007/s10593-008-0115-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Synthesis and stereoisomerism of derivatives of tert-butyl 7-alkylideneceph-3-em-4-carboxylate. Chem Heterocycl Compd (N Y) 2008. [DOI: 10.1007/s10593-008-0067-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Separation of Azepinio‐Methyl Derivatives of ES‐Silanates by the Use of Aryl Stationary Phases in HPLC. J LIQ CHROMATOGR R T 2008. [DOI: 10.1080/10826070701853826] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Synthesis and structural modification of tert-butyl ester of 7α-chloro-2-(N,N-dimethylaminomethylene)-3-methyl-1,1-dioxoceph-3-em-4-carboxylic acid. Chem Heterocycl Compd (N Y) 2007. [DOI: 10.1007/s10593-007-0101-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Second Kunitz-type protease inhibitor domain of the human WFIKKN1 protein. JOURNAL OF BIOMOLECULAR NMR 2006; 35:73-8. [PMID: 16791741 DOI: 10.1007/s10858-006-9013-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2006] [Accepted: 03/22/2006] [Indexed: 05/10/2023]
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Structure and influence on stability and activity of the N-terminal propeptide part of lung surfactant protein C. FEBS J 2006; 273:926-35. [PMID: 16478467 DOI: 10.1111/j.1742-4658.2006.05124.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mature lung surfactant protein C (SP-C) corresponds to residues 24-58 of the 21 kDa proSP-C. A late processing intermediate, SP-Ci, corresponding to residues 12-58 of proSP-C, lacks the surface activity of SP-C, and the SP-Ci alpha-helical structure does not unfold in contrast to the metastable nature of the SP-C helix. The NMR structure of an analogue of SP-Ci, SP-Ci(1-31), with two palmitoylCys replaced by Phe and four Val replaced by Leu, in dodecylphosphocholine micelles and in ethanol shows that its alpha-helix vs. that of SP-C is extended N-terminally. The Arg-Phe part in SP-Ci that is cleaved to generate SP-C is localized in a turn structure, which is followed by a short segment in extended conformation. Circular dichroism spectroscopy of SP-Ci(1-31) in microsomal or surfactant lipids shows a mixture of helical and extended conformation at pH 6, and a shift to more unordered structure at pH 5. Replacement of the N-terminal hexapeptide segment SPPDYS (known to constitute a signal in intracellular targeting) of SP-Ci with AAAAAA results in a peptide that is mainly unstructured, independent of pH, in microsomal and surfactant lipids. Addition of a synthetic dodecapeptide, corresponding to the propeptide part of SP-Ci, to mature SP-C results in slower aggregation kinetics and altered amyloid fibril formation, and reduces the surface activity of phospholipid-bound SP-C. These data suggest that the propeptide part of SP-Ci prevents unfolding by locking the N-terminal part of the helix, and that acidic pH results in structural disordering of the region that is proteolytically cleaved to generate SP-C.
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NMR structure of the WIF domain of the human Wnt-inhibitory factor-1. J Mol Biol 2006; 357:942-50. [PMID: 16476441 DOI: 10.1016/j.jmb.2006.01.047] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2005] [Revised: 01/05/2006] [Accepted: 01/11/2006] [Indexed: 11/17/2022]
Abstract
The human Wnt-binding protein Wnt-inhibitory factor-1 (WIF-1) comprises an N-terminal WIF module followed by five EGF-like repeats. Here we report the three-dimensional structure of the WIF domain of WIF-1 determined by NMR spectroscopy. The fold consists of an eight-stranded beta-sandwich reminiscent of the immunoglobulin fold. Residual detergent (Brij-35) used in the refolding protocol was found to bind tightly to the WIF domain. The binding site was identified by intermolecular nuclear Overhauser effects observed between the WIF domain and the alkyl chain of the detergent. The results point to a possible role of WIF domains as a recognition motif of Wnt and Drosophila Hedgehog proteins that are activated by palmitoylation.
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