A system for catalytic trimerization of ethylene utilizing CrCl3(THF)3 and a diphosphine ligand PNPOMe [= (o-MeO-C6H4)2PN(Me)P(o-MeO-C6H4)2] has been investigated. The coordination chemistry of chromium with PNPOMe has been explored, and (PNPOMe)CrCl3 and (PNPOMe)CrPh3 (3) have been synthesized by ether displacement from chromium(III) precursors. Salt metathesis of (PNPOMe)CrCl3 with o,o'-biphe...

Cationic titanium(IV) complexes with ansa-(eta(5)-cyclopentadienyl,eta(6)-arene) ligands were synthesized and characterized by X-ray crystallography. The strength of the metal-arene interaction in these systems was studied by variable-temperature NMR spectroscopy. Complexes with a C(1) bridge between the cyclopentadienyl and arene moieties feature hemilabile coordination behavior of the ligand ...

The effect of composition and morphology of bimetallic Pd-Au nanoclusters on their chemical reactivity has been studied with acetylene decomposition and conversion to ethylene and benzene as the chemical probe. High resolution transmission electron microscopy (HR-TEM) and CO-Temperature Programmed Desorption (TPD) measurements were employed for structure and chemical composition determination. ...

AcrB is a multidrug transporter in the inner membrane of Escherichia coli. It is an obligate homotrimer and forms a tripartite efflux complex with AcrA and TolC. AcrB is the engine of the efflux machinery and determines substrate specificity. Active efflux depends on several functional features including proton translocation across the inner membrane through a proton relay pathway in the transm...

Heat shock transcription factor (HSF) is a multidomain protein that exists as a monomer under normal conditions and is reversibly induced upon heat shock to a trimeric state that binds to DNA with high affinity. The maintenance of the monomeric state is dependent on hydrophobic heptad repeats located at the amino- and carboxy-terminal regions which have been proposed to form an intramolecular c...

The hereditary bone disorder osteogenesis imperfecta is often caused by missense mutations in type I collagen that change one Gly residue to a larger residue and that break the typical (Gly-Xaa-Yaa)(n) sequence pattern. Site-directed mutagenesis in a recombinant bacterial collagen system was used to explore the effects of the Gly mutation position and of the identity of the residue replacing Gl...