Heteromerization of G protein-coupled receptors (GPCRs) can significantly change the functional properties of involved receptors. Various biochemical and biophysical methodologies have been developed in the last two decades to identify and functionally evaluate GPCR heteromers in heterologous cells, with recent approaches focusing on GPCR complex stoichiometry and stability. Yet validation of t...

We have determined the subunit stoichiometry of chicken neuronal nicotinic acetylcholine receptors expressed in Xenopus oocytes by quantitation of the amount of radioactivity in individual subunits of [35S] methionine-labeled receptors. The chicken neuronal nicotinic acetylcholine receptor appears to be a pentamer of two alpha 4 acetylcholine-binding subunits and three beta 2 structural subunit...

The homogeneity range of B i S r C a C u oxides with two-layers ("2212") structure has been investigated with X-ray powder diffraction and electron microprobe determination on materials with nominal Bi2Sr3_J tCaxCu208 + ) , (x = 1-h2 in 0.1 steps) composition and being prepared at two different oxygen partial pressures. The results show Bi over-stoichiometry and a wide range of Sr/Ca substituti...

Pyruvate carboxylase (PC) has important roles in metabolism and is crucial for virulence for some pathogenic bacteria. PC contains biotin carboxylase (BC), carboxyltransferase (CT) and biotin carboxyl carrier protein (BCCP) components. It is a single-chain enzyme in eukaryotes and most bacteria, and functions as a 500 kD homo-tetramer. In contrast, PC is a two-subunit enzyme in a collection of ...

The effects of stoichiometry on the atomic structure and the related mechanical properties of boron carbide (B(4)C) have been studied using density functional theory and quantum molecular dynamics simulations. Computational cells of boron carbide containing up to 960 atoms and spanning compositions ranging from 6.7% to 26.7% carbon were used to determine the effects of stoichiometry on the ato...

We exploit the optical and spatial features of subwavelength nanostructures to examine individual receptors on the plasma membrane of living cells. Receptors were sequestered in portions of the membrane projected into zero-mode waveguides. Using single-step photobleaching of green fluorescent protein incorporated into individual subunits, the resulting spatial isolation was used to measure subu...

Qiang Zhu,1,2,* Li Li,3 Artem R. Oganov,1,2,3,4 and Philip B. Allen3 1Department of Geosciences, Stony Brook University, Stony Brook, New York 11794, USA 2Center for Materials by Design, Institute for Advanced Computational Science, Stony Brook University, New York 11794, USA 3Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA 4Department of Problems o...

We investigated the stoichiometry of the heteromultimeric G protein-coupled inward-recitfier K+ channel (GIRK) formed from GIRK1 and GIRK4 subunits. Multimeric GIRK constructs with several concatenated channel subunits were expressed in Xenopus oocytes. Coexpression of various trimeric constructs with different monomers clearly showed that the functional channel has stoichiometry (GIRK1)2(GIRK4...

Fusidic acid does not inhibit the translocation of N-acetylphenylalanyl-tRNA (N-acetyl-Phe-tRNA), bound nonenzymitally to the ribosomal A-site, when the amount of ribosomes in the reaction mixture is not sufficient to trap all the available elongation factor G (EF-G) in the form of GDP ‘EF-G .fusidic acid .ribosome complexes. Moreover, since only those ribosomes in the reaction mixture that are...

The net primary production of the biosphere is consumed largely by microorganisms; whose metabolism creates the trophic base for detrital foodwebs, drives element cycles, and mediates atmospheric composition. Biogeochemical constraints on microbial catabolism, relative to primary production, create reserves of detrital organic carbon in soils and sediments that exceed the carbon content of the ...