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Full-Text Articles in Medicine and Health Sciences
Myxobacteria Versus Sponge-Derived Alkaloids: The Bengamide Family Identified As Potent Immune Modulating Agents By Scrutiny Of Lc-Ms/Elsd Libraries., Tyler A. Johnson, Johann Sohn, Yvette M Vaske, Kimberly N White, Tanya L Cohen, Helene C Vervoort, Karen Tenney, Frederick A Valeriote, Leonard F Bjeldanes, Phillip Crews
Myxobacteria Versus Sponge-Derived Alkaloids: The Bengamide Family Identified As Potent Immune Modulating Agents By Scrutiny Of Lc-Ms/Elsd Libraries., Tyler A. Johnson, Johann Sohn, Yvette M Vaske, Kimberly N White, Tanya L Cohen, Helene C Vervoort, Karen Tenney, Frederick A Valeriote, Leonard F Bjeldanes, Phillip Crews
Tyler Johnson
A nuclear factor-κB (NF-κB) luciferase assay has been employed to identify the bengamides, previously known for their anti-tumor activity, as a new class of immune modulators. A unique element of this study was that the bengamide analogs were isolated from two disparate sources, Myxococcus virescens (bacterium) and Jaspis coriacea (sponge). Comparative LC-MS/ELSD and NMR analysis facilitated the isolation of M. viriscens derived samples of bengamide E (8) and two congeners, bengamide E' (13) and F' (14) each isolated as an insperable mixture of diastereomers. Additional compounds drawn from the UC, Santa Cruz repository allowed expansion of the structure activity relationship …
The Marine Sponge Metabolite Mycothiazole: A Novel Prototype Mitochondrial Complex I Inhibitor., J Brian Morgan, Fakhri Mahdi, Yang Liu, Veena Coothankandaswamy, Mika B Jekabsons, Tyler A. Johnson, Koneni V Sashidhara, Phillip Crews, Dale G Nagle, Yu-Dong Zhou
The Marine Sponge Metabolite Mycothiazole: A Novel Prototype Mitochondrial Complex I Inhibitor., J Brian Morgan, Fakhri Mahdi, Yang Liu, Veena Coothankandaswamy, Mika B Jekabsons, Tyler A. Johnson, Koneni V Sashidhara, Phillip Crews, Dale G Nagle, Yu-Dong Zhou
Tyler Johnson
A natural product chemistry-based approach was applied to discover small-molecule inhibitors of hypoxia-inducible factor-1 (HIF-1). A Petrosaspongia mycofijiensis marine sponge extract yielded mycothiazole (1), a solid tumor selective compound with no known mechanism for its cell line-dependent cytotoxic activity. Compound 1 inhibited hypoxic HIF-1 signaling in tumor cells (IC(50) 1nM) that correlated with the suppression of hypoxia-stimulated tumor angiogenesis in vitro. However, 1 exhibited pronounced neurotoxicity in vitro. Mechanistic studies revealed that 1 selectively suppresses mitochondrial respiration at complex I (NADH-ubiquinone oxidoreductase). Unlike rotenone, MPP(+), annonaceous acetogenins, piericidin A, and other complex I inhibitors, mycothiazole is a mixed polyketide/peptide-derived compound …
Chemically Diverse Microtubule Stabilizing Agents Initiate Distinct Mitotic Defects And Dysregulated Expression Of Key Mitotic Kinases., Cristina C Rohena, Jiangnan Peng, Tyler A. Johnson, Phillip Crews, Susan L Mooberry
Chemically Diverse Microtubule Stabilizing Agents Initiate Distinct Mitotic Defects And Dysregulated Expression Of Key Mitotic Kinases., Cristina C Rohena, Jiangnan Peng, Tyler A. Johnson, Phillip Crews, Susan L Mooberry
Tyler Johnson
Microtubule stabilizers are some of the most successful drugs used in the treatment of adult solid tumors and yet the molecular events responsible for their antimitotic actions are not well defined. The mitotic events initiated by three structurally and biologically diverse microtubule stabilizers; taccalonolide AJ, laulimalide/fijianolide B and paclitaxel were studied. These microtubule stabilizers cause the formation of aberrant, but structurally distinct mitotic spindles leading to the hypothesis that they differentially affect mitotic signaling. Each microtubule stabilizer initiated different patterns of expression of key mitotic signaling proteins. Taccalonolide AJ causes centrosome separation and disjunction failure to a much greater extent …
Discovery Of Platelet-Type 12-Human Lipoxygenase Selective Inhibitors By High-Throughput Screening Of Structurally Diverse Libraries., Joshua D. Deschamps, Jeffrey T. Gautschi, Stephanie Whitman, Tyler A. Johnson, Nadine C. Gassner, Phillip Crews, Theodore R. Holman
Discovery Of Platelet-Type 12-Human Lipoxygenase Selective Inhibitors By High-Throughput Screening Of Structurally Diverse Libraries., Joshua D. Deschamps, Jeffrey T. Gautschi, Stephanie Whitman, Tyler A. Johnson, Nadine C. Gassner, Phillip Crews, Theodore R. Holman
Tyler Johnson
Human lipoxygenases (hLO) have been implicated in a variety of diseases and cancers and each hLO isozyme appears to have distinct roles in cellular biology. This fact emphasizes the need for discovering selective hLO inhibitors for both understanding the role of specific lipoxygenases in the cell and developing pharmaceutical therapeutics. To this end, we have modified a known lipoxygenase assay for high-throughput (HTP) screening of both the National Cancer Institute (NCI) and the UC Santa Cruz marine extract library (UCSC-MEL) in search of platelet-type 12-hLO (12-hLO) selective inhibitors. The HTP screen led to the characterization of five novel 12-hLO inhibitors …
Crosstalk Between Brca-Fanconi Anemia And Mismatch Repair Pathways Prevents Msh2-Dependent Aberrant Dna Damage Responses, Min Peng, Jenny X. Xie, Anna J. Ucher, Janet Stavnezer, Sharon B. Cantor
Crosstalk Between Brca-Fanconi Anemia And Mismatch Repair Pathways Prevents Msh2-Dependent Aberrant Dna Damage Responses, Min Peng, Jenny X. Xie, Anna J. Ucher, Janet Stavnezer, Sharon B. Cantor
Janet M. Stavnezer
Several proteins in the BRCA-Fanconi anemia (FA) pathway, such as FANCJ, BRCA1, and FANCD2, interact with mismatch repair (MMR) pathway factors, but the significance of this link remains unknown. Unlike the BRCA-FA pathway, the MMR pathway is not essential for cells to survive toxic DNA interstrand crosslinks (ICLs), although MMR proteins bind ICLs and other DNA structures that form at stalled replication forks. We hypothesized that MMR proteins corrupt ICL repair in cells that lack crosstalk between BRCA-FA and MMR pathways. Here, we show that ICL sensitivity of cells lacking the interaction between FANCJ and the MMR protein MLH1 is …
Nonenzymatic Glycosylation Of Erythrocyte Membrane Proteins. Relevance To Diabetes, J A. Miller, Ellen M. Gravallese, H F. Bunn
Nonenzymatic Glycosylation Of Erythrocyte Membrane Proteins. Relevance To Diabetes, J A. Miller, Ellen M. Gravallese, H F. Bunn
Ellen M. Gravallese
Nonenzymatic glycosylation of proteins of the erythrocyte membrane was determined by incubating erythrocyte ghosts with [3H]borohydride. The incorporation of tritium into protein provides a reliable assay of ketoamine linkages. The membrane proteins from 18 patients with diabetes incorporated twice as much radioactivity as membrane proteins from normal erythrocytes. After acid hydrolysis, amino acid analysis showed that the majority of radioactivity was localized to glucosyllysine. Autoradiograms showed that all of the major proteins of the erythrocyte membrane, separated by electrophoresis on sodium dodecyl sulfate gels, contained ketoamine linkages. No protein bands in either normal or diabetic erythrocytes showed significant preferential labeling. …