The visible spectrum of a ligand-bound cytochrome P450 is often used to determine the nature of the interaction between the ligand and the P450. One particularly characteristic form of spectra arises from the coordination of nitrogen-containing ligands to the P450 heme iron. These type II ligands tend to be inhibitors because they stabilize the low reduction potential P450 and prevent oxygen bi...

This analysis considers the structural evidence of a ligand-binding function of the nuclear receptor ultraspiracle (USP). The positions and nature of residues in the ligand-binding domain of USP from six higher insects is evaluated in comparison to the function of conserved residues vertebrate receptors that have been co-crystallized with ligand. USP appears to conserve residues that in vertebr...

The kinetic basis for the reduction in the oxygen affinity of hemoglobin due to carbon dioxide at constant pH, is studied by measuring the deoxygenation rates of oxyhemoglobin with dithionite, as well as the rate of binding of carbon monoxide to deoxyhemoglobin. These studies were performed in buffer containing 0.05 M potassium phosphate, as well as various mixtures of potassium chloride and po...

Direct measurements revealed low oxygen tensions (0.5-4.5% oxygen) in murine lymphoid organs in vivo. To test whether adaptation to changes in oxygen tension may have an effect on lymphocyte functions, T cell differentiation and functions at varying oxygen tensions were studied. These studies show: 1) differentiated CTL deliver Fas ligand- and perforin-dependent lethal hit equally well at all r...

The CuNO3 • C6H4N3(C3H5) compound (I) was obtained by alternating current electrochemical synthesis, starting from an ethanol solution containing Cu(NO3)2 • 3H2O and a mixture of 1- and 2-allylbenzotriazole titrated by HNO3 to pH = 4. The C=C bond of one 1-allylbenzotriazole molecule, the nitrogen atom from another ligand moiety, and two oxygen atoms from two nitrate-anions form a trigonal-pyra...

The origin of the concept of a molecular complex between oxygen and hemoglobin can be traced to Stokes, a century and a half ago. Subsequently, physicochemical concepts of equilibria provided a path to quantitative formulations of these ligand-receptor interactions. Then, it took a quarter of a century before a proper format was prepared in terms of four stoichiometric equilibria and their asso...

phosphoryl containing ligand tri-n-octylphosphine oxide (topo) in dichloromethane has been used as an extracting agent for tetravalent thorium and trivalent europium ions from their 1 m sodium nitrates. the equilibrium data reveal that both ions are extracted as the complexes at 1:3 metal/ligand ratio. the values of conditional extraction equilibrium constant (kex) show the superior extractive ...

Four iridium(III)-containing coordination polymers 1-4 using Ir(ppy)(2)(H(2)dcbpy)PF(6) (L-H(2), ppy = 2-phenylpyridine, H(2)dcbpy = 4,4'-dicarboxy-2,2'-bipyridine) as the bridging ligand, [ZnL(2)]·3DMF·5H(2)O (1), [CdL(2)(H(2)O)(2)]·3DMF·6H(2)O (2), [CoL(2)(H(2)O)(2)]·2DMF·8H(2)O (3) and [NiL(2)(H(2)O)(2)]·3DMF·6H(2)O (4), have been synthesized and structurally characterized. The emissions fro...

The reaction of N, N-bis(2-hydroxyethyl)glycine (bicine; bicH(3)) with Cd(O(2)CPh)(2) · 2H(2)O in MeOH yielded the polymeric compound [Cd(2)(O(2)CPh)(2)(bicH(2))(2)](n)(1). The complex crystallizes in the tetragonal space group P4(1)2(1)2. The lattice constants are a = b = 12.737(5) and c = 18.288(7) Å. The compound contains chains of repeating {Cd(2)(O(2)CPh)(2)(bicH(2))(2)} units. One Cd(II) ...