The cleavage of one N-O bond in NO2 by two equivalents of Mo(NRAr)3 has been shown to occur to form molybdenum oxide and nitrosyl complexes. The mechanism and electronic rearrangement of this reaction was investigated using density functional theory, using both a model Mo(NH2)3 system and the full [N((t)Bu)(3,5-dimethylphenyl)] experimental ligand. For the model ligand, several possible modes o...

Aggrecan, the major proteoglycan of cartilage that provides its mechanical properties of compressibility and elasticity, is one of the first matrix components to undergo measurable loss in arthritic diseases. Two major sites of proteolytic cleavage have been identified within the interglobular domain (IGD) of the aggrecan core protein, one between amino acids Asn(341)-Phe(342) which is cleaved ...

The title compound, [Cu2(CN)3(C6H18N4)] or [Cu(trien)(CN)Cu(CN)2], where trien is triethyl-ene-tetra-mine, is a mixed-valence complex crystallizing as discrete mol-ecules, with Cu(I) and Cu(II) ions linked by a bridging cyanide group. The Cu(II) ion is in a square-pyramidal coordination environment, with the N atoms of the tetra-dentate trien ligand occupying the basal positions and Cu-N bond l...

Octahedral ruthenium complexes of the type TpRu(L)(NCMe)R [Tp ) hydridotris(pyrazolyl)borate; R ) alkyl or aryl; L ) CO or PMe3] have been shown previously to initiate the C-H activation of aromatic substrates. In order to probe the nature of the C-H activation step, reaction rates have been theoretically obtained for the conversion of TpRu(L)(η-C,C-C6H5X)Me to TpRu(L)(p-C6H4X) and CH4 where X ...

The threshold photoelectron spectrum and threshold photoelectron-photoion coincidence spectra of CHCl2F, CHClF2 and CH2ClF are reported in the range 11.3-24.8 eV. Tunable photoionizing radiation with a resolution of 0.3 nm is provided from a synchrotron source with a vacuum-UV monochromator. The coincidence spectra are recorded continuously as a function of photon energy, allowing yields of the...

The cleavage of a DNA phosphodiester bond by Escherichia coli DNA topoisomerase I and the simultaneous covalent linkage of the enzyme to the 5’-phosphoryl group of the DNA at the cleavage site have been reported previously (Depew, R. E., Liu, L. F., and Wang, J. C. (1978) J. Biol. Chem 253, 511-518; Liu, L. F., and Wang, J. C. (1979) J. Biol. Chem 254, 11082-11088). With either E. coli or Micmc...

Some organophosphorus compounds are toxic because they inhibit acetylcholinesterase (AChE) by phosphylation of the active site serine, forming a stable conjugate: Ser-O-P(O)-(Y)-(XR) (where X can be O, N, or S and Y can be methyl, OR, or SR). The inhibited enzyme can undergo an aging process, during which the X-R moiety is dealkylated by breaking either the P-X or the X-R bond depending on the ...