Correlating enzyme activity and cellular behavior

A photoactivatable phosphorylation sensor used in conjunction with isoform specific inhibitors of protein kinase C enables the enzyme's activity to be monitored inside cells at specific time points during mitosis. PKCbeta was found to be active before, but not after, nuclear envelope breakdown.     

Molecular structure of tetrapropylammonium-2,3-dichloro-5,6-dicyano-p-benzoquinone compared toM + TCNQ− (M +=Rb+, K+, Cs+, or organic cations; TCNQ−=tetracyanoquinomethane) charge-transfer complexes

The crystal and molecular structure of tetrapropylammonium-2,3-dichloro-5,6-dicyano-p-benzoquinone (TPA⁺ DDQ^–) has been determined from single-crystal X-ray diffraction analysis. The crystals are monoclinic, space groupP2₁/n, witha=13.297(5),b=12.851(4),c=13.099(5) Å,=101.34(2)°, andZ=4. The compound consists of discrete (DDQ) ₂ ^2– anion dimers and two TPA⁺ cations inserted between the (DDQ) ₂ ^2– dimers, with an infinite stack running along b of the type (DDQ) ₂ ^2– [(C₃H₇)₄N⁺] (DDQ) ₂ ^2– 2[(C₃H₇)₄N⁺]The (DDQ) ₂ ^2– anion is formed by two DDQ^– anions dimerized through a crystallographic center of symmetry; each DDQ^– moiety is nearly planar and exhibits molecular dimensions similar to those found in analogous compounds. The comparison between the (DDQ) ₂ ^2– anion and a neutral DDQ molecule clearly shows that bond lengths are markedly influenced by the 2-anionic charge. Tetrapropylammomum cation assumes a distorted tetrahedral configuration as observed in TEA⁺ DDQ^– (TEA⁺=tetraethylammonium cation). The data are discussed in connection with the electrical conductivity of organic metals.     

The structural characteristics of amorphous D2O ice by neutron diffraction

Neutron diffraction measurements have been made at several wavelengths for vapor-deposited D₂O ice at 10 K. The observed structure factor exhibits more oscillatory features than corresponding measurements on liquid D₂O water, indicating an ammorphous phase which has strong intermolecular spatial correlations. A detailed examination of the data shows that this is strongly influenced by hydrogen-bonding effects and that the local environment for each molecule is very similar to that in crystalline ice. The predictions of Boutron and Alben, based on a continuous random network model, are found to be in excellent agreement with the data.     

Separation of two (possibly unbounded) components of the spectrum of a linear operator

LetX be a complex Banach space andA: D(A)X a densely defined closed linear operator whose resolvent set contains the real line and for which (–A)^–1 is bounded onR. We give a necessary and sufficient condition, in terms of the complex powers ofA and –A, for the existence of a decompositionX=X ₊X _–, whereX _± are closed subspaces, invariant forA, the spectra of the reduced operatorsA _± are {(A);Im>0} and {(A);Im<0} respectively, and (–A _±)^–1 is bounded forIm0.Finally we give an example of an operator in anL ^p-type space for which the decomposition exists if 1<p<+ and does not exist ifp=1.     

Improved search for nu(mu) --> nu(e) oscillation in a long-baseline accelerator experiment

We performed an improved search for nu(mu) --> nu(e) oscillation with the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment, using the full data sample of 9.2 x 10(19) protons on target. No evidence for a nu(e) appearance signal was found, and we set bounds on the nu(mu) --> nu(e) oscillation parameters. At Deltam(2)=2.8 x 10(-3) eV(2), the best-fit value of the K2Knu(mu) disappearance analysis, we set an upper limit of sin(2)2theta(mue) < 0.13 at a 90% confidence level.     

The rotational spectrum of 13C2HD in the ground and excited bending states

The pure rotational spectrum of ¹³C₂HD was recorded in the range 100–700 GHz. Lines belonging to the ground vibrational state were observed from J^″ = 1 to J^″ = 11. Several absorption lines were also detected in the bending states v₄ = 1 (Π), v₅ = 1 (Π), v₄ = 2 (Σ⁺ and Δ), v₅ = 2 (Σ⁺ and Δ), v₄ = v₅ = 1 (Σ^?, Σ⁺ and Δ), v₄ = 3 (Π and Φ) and v₅ = 3 (Π and Φ). The transition frequencies measured in this work were fitted together with all the infrared lines available in the literature. The global fit allowed a very accurate determination of the vibrational, rotational and ?-type interaction parameters for the bending states of this molecule.     

Comparison of the absorption, emission, and resonance Raman spectra of 7-hydroxyquinoline and 8-bromo-7-hydroxyquinoline caged acetate

To better understand the deprotection reaction of the new promising phototrigger compound BHQ-OAc (8-bromo-7-hydroxyquinoline acetate), we present a detailed comparison of the UV-vis absorption, resonance Raman, and fluorescence spectra of BHQ-OAc with its parent compound 7-hydroxyquinoline in different solvents. The steady-state absorption and resonance Raman spectra provide fundamental information about the structure, properties, and population distribution of the different prototropic forms present under the different solvent conditions examined. The species present in the excited states that emit strongly were detected by fluorescence spectra. It is shown that the ground-state tautomerization process of BHQ-OAc is disfavored compared with that of 7-HQ in aqueous solutions. The observation of the tautomeric form of BHQ-OAc in neutral aqueous solutions demonstrates the occurrence of the excited-state proton-transfer process, which would be a competing process for the deprotection reaction of BHQ-OAc in aqueous solutions.     

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