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  1. Article ; Online: Cryo-EM structures of HIV-1 trimer bound to CD4-mimetics BNM-III-170 and M48U1 adopt a CD4-bound open conformation

    Claudia A. Jette / Christopher O. Barnes / Sharon M. Kirk / Bruno Melillo / Amos B. Smith / Pamela J. Bjorkman

    Nature Communications, Vol 12, Iss 1, Pp 1-

    2021  Volume 10

    Abstract: Conformational changes of HIV’s Env protein are required for its function in fusing the viral and host cell membranes. Here the authors describe how two small molecules alter the confirmation of Env trimers, and show they can induce structural changes ... ...

    Abstract Conformational changes of HIV’s Env protein are required for its function in fusing the viral and host cell membranes. Here the authors describe how two small molecules alter the confirmation of Env trimers, and show they can induce structural changes similar to those occur upon receptor binding.
    Keywords Science ; Q
    Language English
    Publishing date 2021-03-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article: Oxidative [1,2]-Brook Rearrangements Exploiting Single-Electron Transfer: Photoredox-Catalyzed Alkylations and Arylations

    Deng, Yifan / Amos B. Smith / Qi Liu

    Journal of the American Chemical Society. 2017 July 19, v. 139, no. 28

    2017  

    Abstract: Oxidative [1,2]-Brook rearrangements via hypervalent silicon intermediates induced by photoredox-catalyzed single-electron transfer have been achieved, permitting the formation of reactive radical species that can engage in alkylations and arylations. ...

    Abstract Oxidative [1,2]-Brook rearrangements via hypervalent silicon intermediates induced by photoredox-catalyzed single-electron transfer have been achieved, permitting the formation of reactive radical species that can engage in alkylations and arylations.
    Keywords arylation ; silicon
    Language English
    Dates of publication 2017-0719
    Size p. 9487-9490.
    Publishing place American Chemical Society
    Document type Article
    ZDB-ID 3155-0
    ISSN 1520-5126 ; 0002-7863
    ISSN (online) 1520-5126
    ISSN 0002-7863
    DOI 10.1021/jacs.7b05165
    Database NAL-Catalogue (AGRICOLA)

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  3. Article ; Online: The Marine-Derived Macrolactone Mandelalide A Is an Indirect Activator of AMPK

    Daphne R. Mattos / Xuemei Wan / Jeffrey D. Serrill / Minh H. Nguyen / Ian R. Humphreys / Benoit Viollet / Amos B. Smith / Kerry L. McPhail / Jane E. Ishmael

    Marine Drugs, Vol 20, Iss 418, p

    2022  Volume 418

    Abstract: The mandelalides are complex macrolactone natural products with distinct macrocycle motifs and a bioactivity profile that is heavily influenced by compound glycosylation. Mandelalides A and B are direct inhibitors of mitochondrial ATP synthase (complex V) ...

    Abstract The mandelalides are complex macrolactone natural products with distinct macrocycle motifs and a bioactivity profile that is heavily influenced by compound glycosylation. Mandelalides A and B are direct inhibitors of mitochondrial ATP synthase (complex V) and therefore more toxic to mammalian cells with an oxidative metabolic phenotype. To provide further insight into the pharmacology of the mandelalides, we studied the AMP-activated protein kinase (AMPK) energy stress pathway and report that mandelalide A is an indirect activator of AMPK. Wild-type mouse embryonic fibroblasts (MEFs) and representative human non-small cell lung cancer (NSCLC) cells showed statistically significant increases in phospho-AMPK (Thr172) and phospho-ACC (Ser79) in response to mandelalide A. Mandelalide L, which also harbors an A-type macrocycle, induced similar increases in phospho-AMPK (Thr172) and phospho-ACC (Ser79) in U87-MG glioblastoma cells. In contrast, MEFs co-treated with an AMPK inhibitor (dorsomorphin), AMPKα-null MEFs, or NSCLC cells lacking liver kinase B1 (LKB1) lacked this activity. Mandelalide A was significantly more cytotoxic to AMPKα-null MEFs than wild-type cells, suggesting that AMPK activation serves as a protective response to mandelalide-induced depletion of cellular ATP. However, LKB1 status alone was not predictive of the antiproliferative effects of mandelalide A against NSCLC cells. When EGFR status was considered, erlotinib and mandelalide A showed strong cytotoxic synergy in combination against erlotinib-resistant 11-18 NSCLC cells but not against erlotinib-sensitive PC-9 cells. Finally, prolonged exposures rendered mandelalide A, a potent and efficacious cytotoxin, against a panel of human glioblastoma cell types regardless of the underlying metabolic phenotype of the cell. These results add biological relevance to the mandelalide series and provide the basis for their further pre-clinical evaluation as ATP synthase inhibitors and secondary activators of AMPK.
    Keywords OXPHOS ; polyketide ; ATP synthase ; ATPase ; oxidative phosphorylation ; AMP-activated protein kinase ; Biology (General) ; QH301-705.5
    Subject code 500 ; 570
    Language English
    Publishing date 2022-06-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Elicitation of Cluster A and Co-Receptor Binding Site Antibodies are Required to Eliminate HIV-1 Infected Cells

    Guillaume Beaudoin-Bussières / Jérémie Prévost / Gabrielle Gendron-Lepage / Bruno Melillo / Junhua Chen / Amos B. Smith III / Marzena Pazgier / Andrés Finzi

    Microorganisms, Vol 8, Iss 710, p

    2020  Volume 710

    Abstract: HIV-1-infected individuals raise a polyclonal antibody response targeting multiple envelope glycoprotein (Env) epitopes. Interestingly, two classes of non-neutralizing CD4-induced (CD4i) antibodies, present in the majority of HIV-1-infected individuals ... ...

    Abstract HIV-1-infected individuals raise a polyclonal antibody response targeting multiple envelope glycoprotein (Env) epitopes. Interestingly, two classes of non-neutralizing CD4-induced (CD4i) antibodies, present in the majority of HIV-1-infected individuals have been described to mediate antibody-dependent cellular cytotoxicity (ADCC) in the presence of small CD4 mimetic compounds (CD4mc). These antibodies recognize the coreceptor binding site (CoRBS) and the constant region one and two (C1C2 or inner domain cluster A) of the gp120. In combination with CD4mc they have been shown to stabilize an antibody-vulnerable Env conformation, known as State 2A. Here we evaluated the importance of these two families of Abs in ADCC responses by immunizing guinea pigs with gp120 immunogens that have been modified to elicit or not these types of antibodies. Underlying the importance of anti-CoRBS and anti-cluster A Abs in stabilizing State 2A, ADCC responses were only observed in the presence of these two types of CD4i antibodies. Altogether, our results suggest that these two families of CD4i antibodies must be taken into account when considering future strategies relying on the use of CD4mc to eliminate HIV-1-infected cells in vivo.
    Keywords HIV-1 ; ADCC ; cluster A ; coreceptor binding site ; guinea pigs ; small CD4 mimetics ; Biology (General) ; QH301-705.5
    Subject code 570
    Language English
    Publishing date 2020-05-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article: Spirastrellolide E: synthesis of an advanced C(1)–C(24) southern hemisphere

    Sokolsky, Alexander / Xiaozhao Wang / Amos B. Smith

    Tetrahedron letters. 2015 June 03, v. 56

    2015  

    Abstract: The synthesis of a C(1)–C(24) advanced southern hemisphere fragment towards the total synthesis of spirastrellolide E has been achieved. Highlights of the route include a highly convergent Type I Anion Relay Chemistry (ARC) tactic for fragment assembly, ...

    Abstract The synthesis of a C(1)–C(24) advanced southern hemisphere fragment towards the total synthesis of spirastrellolide E has been achieved. Highlights of the route include a highly convergent Type I Anion Relay Chemistry (ARC) tactic for fragment assembly, in conjunction with a directed, regioselective gold-catalyzed alkyne functionalization to generate the central unsaturated [6,6]-spiroketal.
    Keywords alkynes ; chemical reactions ; chemical structure
    Language English
    Dates of publication 2015-0603
    Size p. 3160-3164.
    Publishing place Elsevier Ltd
    Document type Article
    ZDB-ID 204287-3
    ISSN 1873-3581 ; 0040-4039
    ISSN (online) 1873-3581
    ISSN 0040-4039
    DOI 10.1016/j.tetlet.2014.12.026
    Database NAL-Catalogue (AGRICOLA)

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    In stock of ZB MED Cologne/Königswinter

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  6. Article: Type II Anion Relay Chemistry: Conformational Constraints To Achieve Effective [1,5]-Vinyl Brook Rearrangements

    Liu, Qi / Amos B. Smith / K. N. Houk / Xiao Zhang / Yong Liang / Yu Chen

    Journal of the American Chemical Society. 2017 June 28, v. 139, no. 25

    2017  

    Abstract: The design, synthesis, and evaluation of bifunctional linchpins, conformationally anchored on six-membered rings to achieve efficient [1,5]-Brook rearrangements involving vinyl silanes have been achieved. The restrained linchpins were subsequently ... ...

    Abstract The design, synthesis, and evaluation of bifunctional linchpins, conformationally anchored on six-membered rings to achieve efficient [1,5]-Brook rearrangements involving vinyl silanes have been achieved. The restrained linchpins were subsequently exploited in type II anion relay chemistry (ARC) to permit both alkylations and Pd-mediated cross-coupling reactions (CCR) of sp2 stabilized carbanions. DFT calculations were then employed to understand the mechanism and reactivity trends of [1,4]- and [1,5]-vinyl Brook rearrangements to provide insight on the role of the required copper reagent and the substrate geometry.
    Keywords copper ; cross-coupling reactions ; geometry ; silanes
    Language English
    Dates of publication 2017-0628
    Size p. 8710-8717.
    Publishing place American Chemical Society
    Document type Article
    ZDB-ID 3155-0
    ISSN 1520-5126 ; 0002-7863
    ISSN (online) 1520-5126
    ISSN 0002-7863
    DOI 10.1021/jacs.7b04149
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  7. Article: Improved Dose-Response Relationship of (+)-Discodermolide-Taxol Hybrid Congeners

    Nadaradjane, Celine / Alicia Rodriguez-Gabin / Amos B. Smith / Chia-Ping Huang Yang / Hayley M. McDaid / Keizo Sugasawa / Kenny Ye / Onur Atasoylu / Susan Band Horwitz

    Journal of natural products. 2018 Mar. 09, v. 81, no. 3

    2018  

    Abstract: Discodermolide is a microtubule-stabilizing agent with potential for the treatment of taxol-refractory malignancies. (+)-Discodermolide congeners containing the C-3′-phenyl side chain of taxol (paclitaxel) were synthesized based on computational ... ...

    Abstract (+)-Discodermolide is a microtubule-stabilizing agent with potential for the treatment of taxol-refractory malignancies. (+)-Discodermolide congeners containing the C-3′-phenyl side chain of taxol (paclitaxel) were synthesized based on computational docking models predicting this moiety would fill an aromatic pocket of β-tubulin insufficiently occupied by (+)-discodermolide, thereby conferring improved ligand–target interaction. It was recently demonstrated, however, that the C-3′-phenyl side chain occupied a different space, instead extending toward the M-loop of β-tubulin, where it induced a helical conformation, hypothesized to improve lateral contacts between adjacent microtubule protofilaments. This insight led us to evaluate the biological activity of hybrid congeners using a panel of genetically diverse cancer cell lines. Hybrid molecules retained the same tubulin-polymerizing profile as (+)-discodermolide. Since (+)-discodermolide is a potent inducer of accelerated senescence, a fate that contributes to drug resistance, congeners were also screened for senescence induction. Flow cytometric and transcriptional analysis revealed that the hybrids largely retained the senescence-inducing properties of (+)-discodermolide. In taxol-sensitive cell models, the congeners had improved dose-response parameters relative to (+)-discodermolide and, in some cases, were superior to taxol. However, in cells susceptible to senescence, EMax increased without concomitant improvements in EC50 such that overall dose-response profiles resembled that of (+)-discodermolide.
    Keywords bioactive properties ; cell lines ; dose response ; drug resistance ; flow cytometry ; median effective concentration ; microtubules ; models ; moieties ; neoplasm cells ; neoplasms ; paclitaxel ; prediction ; transcription (genetics) ; tubulin
    Language English
    Dates of publication 2018-0309
    Size p. 607-615.
    Publishing place American Chemical Society and American Society of Pharmacognosy
    Document type Article
    ZDB-ID 304325-3
    ISSN 1520-6025 ; 0163-3864
    ISSN (online) 1520-6025
    ISSN 0163-3864
    DOI 10.1021/acs.jnatprod.8b00111
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    Zs.A 1144: Show issues Location:
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  8. Article ; Online: Publisher Correction

    Alon Herschhorn / Christopher Gu / Francesca Moraca / Xiaochu Ma / Mark Farrell / Amos B. Smith / Marie Pancera / Peter D. Kwong / Arne Schön / Ernesto Freire / Cameron Abrams / Scott C. Blanchard / Walther Mothes / Joseph G. Sodroski

    Nature Communications, Vol 9, Iss 1, Pp 1-

    The β20–β21 of gp120 is a regulatory switch for HIV-1 Env conformational transitions

    2018  Volume 1

    Abstract: The original version of this Article contained an error in the spelling of the author Amos B. Smith, III, which was incorrectly given as Amos B. SmithIII. This has now been corrected in both the PDF and HTML versions of the Article. ...

    Abstract The original version of this Article contained an error in the spelling of the author Amos B. Smith, III, which was incorrectly given as Amos B. SmithIII. This has now been corrected in both the PDF and HTML versions of the Article.
    Keywords Science ; Q
    Language English
    Publishing date 2018-01-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: Publisher Correction

    Alon Herschhorn / Christopher Gu / Francesca Moraca / Xiaochu Ma / Mark Farrell / Amos B. Smith / Marie Pancera / Peter D. Kwong / Arne Schön / Ernesto Freire / Cameron Abrams / Scott C. Blanchard / Walther Mothes / Joseph G. Sodroski

    Nature Communications, Vol 9, Iss 1, Pp 1-

    The β20–β21 of gp120 is a regulatory switch for HIV-1 Env conformational transitions

    2018  Volume 1

    Abstract: The original version of this Article contained an error in the spelling of the author Amos B. Smith, III, which was incorrectly given as Amos B. SmithIII. This has now been corrected in both the PDF and HTML versions of the Article. ...

    Abstract The original version of this Article contained an error in the spelling of the author Amos B. Smith, III, which was incorrectly given as Amos B. SmithIII. This has now been corrected in both the PDF and HTML versions of the Article.
    Keywords Science ; Q
    Language English
    Publishing date 2018-01-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article ; Online: The β20–β21 of gp120 is a regulatory switch for HIV-1 Env conformational transitions

    Alon Herschhorn / Christopher Gu / Francesca Moraca / Xiaochu Ma / Mark Farrell / Amos B. Smith / Marie Pancera / Peter D. Kwong / Arne Schön / Ernesto Freire / Cameron Abrams / Scott C. Blanchard / Walther Mothes / Joseph G. Sodroski

    Nature Communications, Vol 8, Iss 1, Pp 1-

    2017  Volume 12

    Abstract: Binding of viral envelope glycoproteins (Env) to the host cell CD4 receptor mediates HIV-1 entry. Here, the authors develop compounds that inhibit the CD4-induced conformational changes in Env and show that the gp120 β20-β21 element is a key regulator ... ...

    Abstract Binding of viral envelope glycoproteins (Env) to the host cell CD4 receptor mediates HIV-1 entry. Here, the authors develop compounds that inhibit the CD4-induced conformational changes in Env and show that the gp120 β20-β21 element is a key regulator for Env transitions.
    Keywords Science ; Q
    Language English
    Publishing date 2017-10-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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