Irene Arjona Medina

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G protein-gated inwardly rectifying potassium (GIRK) channels are a family of K(+)-selective ion channels that slow the firing rate of neurons and cardiac myocytes. GIRK channels are directly bound and activated by the G protein G beta gamma subunit. As heterotetramers, they comprise the GIRK1 and the GIRK2, -3, or -4 subunits. Here we show that GIRK1 but(More)
The cardiac G protein-gated K+ channel, IKACh, is directly activated by G protein beta gamma subunits (Gbeta gamma). IKAChis composed of two inward rectifier K+ channel subunits, GIRK1 and GIRK4. Gbeta gamma binds to both GIRK1 and GIRK4 subunits of the heteromultimeric IKACh. Here we delineate the Gbeta gamma binding regions of IKACh by studying direct(More)
A fungal metabolite, BMS-182123, which inhibited bacterial endotoxin-induced production of tumor necrosis factor (TNF-alpha) in murine macrophages and human peripheral blood monocytes (in vitro), was isolated from the culture broth of Penicillium chrysogenum strain V39673. The effective BMS-182123 concentration (IC50) resulting in 50% inhibition of(More)
Daily oral treatment with the cyclopentyl 2'-deoxyguanosine nucleoside BMS-200475 at doses ranging from 0.02 to 0.5 mg/kg of body weight for 1 to 3 months effectively reduced the level of woodchuck hepatitis virus (WHV) viremia in chronically infected woodchucks as measured by reductions in serum WHV DNA levels and endogenous hepadnaviral polymerase(More)
The muscarinic-gated atrial potassium channel IKACh has been well characterized functionally, and has been an excellent model system for studying G protein/effector interactions. Complementary DNAs encoding the composite subunits of IKACh have been identified, allowing direct probing of structural and functional features of the channel. Here, we highlight(More)
We report the synthesis of thirty-six Sansalvamide A derivatives, and their biological activity against colon cancer HT-29 cell line, a microsatellite stable (MSS) colon cancer cell-line. The thirty-six compounds can be divided into three subsets, where the first subset of compounds contains L-amino acids, the second subset contains D-amino acids, and the(More)
Entecavir (ETV) is a guanosine nucleoside analogue with potent antiviral efficacy in woodchucks chronically infected with woodchuck hepatitis virus. To explore the consequences of prolonged virus suppression, woodchucks received ETV orally for 8 weeks and then weekly for 12 months. Of the 6 animals withdrawn from therapy and monitored for an additional 28(More)
Lobucavir (BMS-180194), a cyclobutyl-guanosine nucleoside analogue, effectively reduced WHV-viremia in chronically infected carrier woodchucks (Marmota monax) by daily per os treatment. WHV-viremia in the animals was measured by the serum content of hybridizable WHV-genomic DNA. Lobucavir, given at daily doses of 10 and 20 mg/kg body weight, reduced(More)
Holliday junctions (HJs) are formed as transient DNA intermediates during site-specific and homologous recombination. Both of these genetic exchange pathways are critical for normal DNA metabolism and repair. Trapping HJs leads to bacterial cell death by preventing proper segregation of the resulting interlinked chromosomes. Macrocyclic peptides designed to(More)
Described are the syntheses of 14 derivatives of the natural product Sansalvamide A, where two are more active against HCT 116 colon cancer cell lines than the natural product. These derivatives were synthesized using a combinatorial-type strategy that permits elucidation of the amino acid role in the cytotoxicity, and they lay the groundwork for(More)