158 research outputs found

    Terpendole E, a Kinesin Eg5 Inhibitor, Is a Key Biosynthetic Intermediate of Indole-Diterpenes in the Producing Fungus Chaunopycnis alba

    Get PDF
    SummaryTerpendole E is the first natural product inhibitor of kinesin Eg5. Because terpendole E production is unstable, we isolated and analyzed the terpendole E biosynthetic gene cluster, which consists of seven genes encoding three P450 monooxygenases (TerP, TerQ, and TerK), an FAD-dependent monooxygenase (TerM), a terpene cyclase (TerB), and two prenyltransferases (TerC and TerF). Gene knockout and feeding experiments revealed that terpendole E is a key intermediate in terpendole biosynthesis and is produced by the action of the key enzyme TerQ from paspaline, a common biosynthetic intermediate of indole-diterpenes. TerP converts terpendole E to a downstream intermediate specific to terpendole biosynthesis and converts paspaline to shunt metabolites. We successfully overproduced terpendole E by disrupting the terP gene. We propose that terpendole E is a key biosynthetic intermediate of terpendoles and related indole-diterpenes

    An efficient synthesis of cycloalkane-1,3-dione-2-spirocyclopropanes from 1,3-cycloalkanediones using (1-aryl-2-bromoethyl)dimethylsulfonium bromides: application to a one-pot synthesis of tetrahydroindol-4(5H)-one

    Get PDF
    An efficient synthesis of cyclohexane- and cyclopentane-1,3-dione-2-spirocyclopropanes from 1,3-cycloalkanediones using sulfonium salts was achieved. The reaction of 1,3-cycloalkanediones with (1-aryl-2-bromoethyl)dimethylsulfonium bromides and powdered K2CO3 in EtOAc provided the corresponding spirocyclopropanes in high yields. Furthermore, a one-pot synthesis of tetrahydroindol-4(5H)-one from 1,3-cyclohexanedione was achieved by using the present protocol and a sequential ring-opening cyclization of spirocyclopropane with a primary amine

    Analysis of plasmin generation and clot lysis of plasma fibrinogen purified from a heterozygous dysfibrinogenemia, B beta Gly15Cys (Hamamatsu II)

    Get PDF
    This is a non-final version of an article published in final form in Blood Coagulation & Fibrinolysis. 20(8):726-732, December 2009.We found a heterozygous dysfibrinogenemia caused by the substitution of B beta Gly15Cys and designated it fibrinogen Hamamatsu II (H-II). Although the propositus suffered an infarction of the medulla oblongata, other thrombotic risk factors, paradoxical cerebral infarction, and arterial dissection were not found. To determine whether the delayed lysis of fibrin clots or not in the context of the B beta Gly15Cys substitution, we examined the clot lysis and plasmin generation of propositus' fibrinogen. Fibrinogen was purified from the propositus' and normal control plasma by immunoaffinity chromatography and was used for the following experiments: sodium dodecyl sulfate-polyacrylamide gel electrophoresis, fibrin polymerization, scanning electron microscopic observation of fibrin clot and fibers, clot lysis, and tissue-type plasminogen activator-mediated plasminogen activation. The H-II plasma fibrinogen showed the presence of albumin-binding variant forms, a dimeric molecule of variant fibrinogen, and impairment of lateral aggregation during fibrin polymerization. The H-II fibrin clot showed lower density of bundles and thinner diameters of fibers than in the normal fibrin clot. In the clot lysis experiments with overlaid plasmin, H-II fibrin showed a similar lysis period and lysis rate to the normal control. Moreover, plasmin generation from a mixture of thrombin, tissue-type plasminogen activator, plasminogen, and H-II fibrinogen also showed a similar rate to normal fibrinogen. Although the propositus suffered an infarction, the present study did not observe delayed clot lysis, that is, the clot was not resistant to plasmin degradation. Therefore, we did not clarify an association between the B beta Gly15Cys dysfibrinogenemia and arterial thrombosis.ArticleBLOOD COAGULATION & FIBRINOLYSIS. 20(8):726-732 (2009)journal articl

    Heterozygous B beta-chain C-terminal 12 amino acid elongation variant, B beta X462W (Kyoto VI), showed dysfibrinogenemia

    Get PDF
    A heterozygous patient with dysfibrinogenemia with slight bleeding and no thrombotic complications was diagnosed with fibrinogen Kyoto VI (K-VI). To elucidate the genetic mutation(s) and characterize the variant protein, we performed the following experiments and compared with identical and similar variants that have already been reported. The proposita's PCR-amplified DNA was analyzed by sequencing and her purified plasma fibrinogen underwent SDS-PAGE followed by immunoblotting, fibrin polymerization, and scanning electron microscopic observation of fibrin clot and fibers. Sequence analyses showed that K-VI fibrinogen substituted W (TGG) for terminal codon (TAG), resulting in 12 amino acid elongation 462-473 (WSPIRRFLLFCM) in the B beta-chain. Protein analyses indicated that the presence of some albumin-binding variant fibrinogens and a dimeric molecule of variant fibrinogens reduced fibrin polymerization, with a thinner fiber and aberrant fibrin network. These results are almost the same as for the identical variant of Magdeburg, however, different from the similar variant of Osaka VI [ 12 amino acid elongation 462-473 (KSPIRRFLLFCM) in the B beta-chain] in the presence of variant forms and clot structure. We speculate the side-chain difference at 462 residues, W in K-VI, K in Osaka VI, and/or the difference in the presence of disulfide bridged forms of variant fibrinogens, led to the notable difference in the fibrin bundle network. Although a strong evolutional and structural association between B beta-chain and gamma-chain molecules is established, the corresponding recombinant 15 residue elongation variants of the fibrinogen gamma-chain showed reduced assembly and secretion.ArticleBLOOD COAGULATION & FIBRINOLYSIS. 23(1):87-90 (2012)journal articl

    Differential roles of prostaglandin E-type receptors in activation of hypoxia-inducible factor 1 by prostaglandin E1 in vascular-derived cells under non-hypoxic conditions

    Get PDF
    Prostaglandin E1 (PGE1), known pharmaceutically as alprostadil, has vasodilatory properties and is used widely in various clinical settings. In addition to acute vasodilatory properties, PGE1 may exert beneficial effects by altering protein expression of vascular cells. PGE1 is reported to be a potent stimulator of angiogenesis via upregulation of VEGF expression, which is under the control of the transcription factor hypoxia-inducible factor 1 (HIF-1). However, the molecular mechanisms behind the phenomenon are largely unknown. In the present study, we investigated the mechanism by which PGE1 induces HIF-1 activation and VEGF gene expression in human aortic smooth muscle cells (HASMCs) and human umbilical vein endothelial cells (HUVECs), both vascular-derived cells. HUVECs and HASMCs were treated with PGE1 at clinically relevant concentrations under 20% O2 conditions and HIF-1 protein expression was investigated. Expression of HIF- 1α protein and the HIF-1-downstream genes were low under 20% O2 conditions and increased in response to PGE1 treatment in both HUVECs and HASMCs in a dose- and time-dependent manner under 20% O2 conditions as comparable to exposure to 1% O2 conditions. Studies using EP-receptor-specific agonists and antagonists revealed that EP1 and EP3 are critical to PGE1-induced HIF-1 activation. In vitro vascular permeability assays using HUVECs indicated that PGE1 increased vascular permeability in HUVECs. Thus, we demonstrate that PGE1 induces HIF- 1α protein expression and HIF-1 activation under non-hypoxic conditions and also provide evidence that the activity of multiple signal transduction pathways downstream of EP1 and EP3 receptors is required for HIF-1 activation

    Integrable discretizations of derivative nonlinear Schroedinger equations

    Full text link
    We propose integrable discretizations of derivative nonlinear Schroedinger (DNLS) equations such as the Kaup-Newell equation, the Chen-Lee-Liu equation and the Gerdjikov-Ivanov equation by constructing Lax pairs. The discrete DNLS systems admit the reduction of complex conjugation between two dependent variables and possess bi-Hamiltonian structure. Through transformations of variables and reductions, we obtain novel integrable discretizations of the nonlinear Schroedinger (NLS), modified KdV (mKdV), mixed NLS, matrix NLS, matrix KdV, matrix mKdV, coupled NLS, coupled Hirota, coupled Sasa-Satsuma and Burgers equations. We also discuss integrable discretizations of the sine-Gordon equation, the massive Thirring model and their generalizations.Comment: 24 pages, LaTeX2e (IOP style), final versio

    Hypotensive Effect of Latanoprost/Timolol Versus Travoprost/Timolol Fixed Combinations in NTG Patients: A Randomized, Multicenter, Crossover Clinical Trial

    No full text
    Citation: Shoji T, Sato H, Mizukawa A, et al. Hypotensive effect of latanoprost/timolol versus travoprost/timolol fixed combinations in NTG patients: a randomized, multicenter, cross-over clinical trial. Invest Ophthalmol Vis Sci. 2013;54:6242-6247. DOI:10.1167/iovs.13-11942 PURPOSE. To compare the ocular hypotensive effect of travoprost plus timolol (TTFC) and latanoprost plus timolol fixed combinations (LTFC) in patients with normal-tension glaucoma (NTG). METHODS. A two-sequence 12-week, multicenter, prospective, randomized, single-blinded, crossover clinical trial examined 59 NTG patients. If both eyes were eligible, only one eye (chosen at random) was used for analytical purposes. After a 12-week run-in period with dorzolamide plus timolol fixed combination (DTFC), patients were randomized into one of the two crossover sequences of treatment for 12 weeks with TTFC or LTFC and were subsequently crossed over to the alternative treatment for a further 12 weeks. The primary endpoint was reduction in IOP after 12 weeks of each treatment sequence. The effect of treatment on IOP was assessed using a linear mixed model. RESULTS. The mean baseline IOP was 14.8 6 3.3 mm Hg (95% confidence interval [CI], 14.1-15.3 mm Hg) for treatment with DTFC. The TTFC treatment period showed consistently lower mean IOP compared with LTFC treatment period at all measurement time points. Mean reduction in IOP at 12 weeks was significantly greater in the TTFC group than in the LTFC group (À2.4 6 2.3 mm Hg vs. À1.1 6 2.3 mm Hg; P ¼ 0.021). No interaction between the drug and treatment sequence was detected. The effects of intraocular lens implantation and measurement time were also not significant. The tolerability profiles of both treatments were similar. CONCLUSIONS. The additional reduction in IOP was greater with TTFC than with LTFC, and their tolerability profiles were similar. (http://www.umin.ac.jp/ctr/ number, UMIN 000005974.) Keywords: fixed combination, normal-tension glaucoma, randomized study G laucoma is one of the main causes of blindness and irreversible deterioration of vision worldwide. 1 It affects approximately 70 million people and is the leading cause of irreversible blindness in approximately 10% of those affected. Approximately half of all patients with glaucoma live in East Asia. 5 Normal-tension glaucoma is often used to describe patients with open-angle glaucoma when their untreated IOP is maintained within a statistically normal range. Multicenter clinical trials have confirmed the importance of reducing IOP in patients with POAG and NTG, 8 When two drugs are required to control IOP, there are a number of potential advantages to using a fixed combination, including no risk of drug washout, 9 reduced exposure to preservatives, and ultimately better patient compliance and quality of life. 10 To our knowledge, few studies are available 11 that compare these fixed combinations in Asian patients, particularly those with NTG. Travoprost plus timolol (TTFC) and latanoprost plus timolol fixed combinations (LTFC) are prostaglandin/timolol fixed combinations medication currently available in Japan. Thus, the purpose of the present study was to compare the ocular hypotensive effect of LTFC and TTFC in glaucoma patients not fully controlled with monotherapy

    Symmetrically coupled higher-order nonlinear Schroedinger equations: singularity analysis and integrability

    Full text link
    The integrability of a system of two symmetrically coupled higher-order nonlinear Schr\"{o}dinger equations with parameter coefficients is tested by means of the singularity analysis. It is proven that the system passes the Painlev\'{e} test for integrability only in ten distinct cases, of which two are new. For one of the new cases, a Lax pair and a multi-field generalization are obtained; for the other one, the equations of the system are uncoupled by a nonlinear transformation.Comment: 12 pages, LaTeX2e, IOP style, final version, to appear in J.Phys.A:Math.Ge
    corecore