scholarly journals Rotational spectra of tetracyclic quinolizidine alkaloids: does a water molecule flip sparteine?

2017 ◽  
Vol 19 (27) ◽  
pp. 17553-17559 ◽  
Author(s):  
Alberto Lesarri ◽  
Ruth Pinacho ◽  
Lourdes Enríquez ◽  
José E. Rubio ◽  
Martín Jaraíz ◽  
...  
Keyword(s):  
Water Molecule ◽  
Water Dimer ◽  
Quinolizidine Alkaloids ◽  
Parent Molecule ◽  
Rotational Spectra

Flipping or not flipping? The sparteine–water dimer generated in a jet expansion retains the trans conformation of the parent molecule.

scholarly journals Density functional theory meta GGA study of water adsorption in MIL-53(Cr)

2019 ◽  
Vol 34 (3) ◽  
pp. 227-232 ◽  
Author(s):  
E. Cockayne
Keyword(s):  
Density Functional Theory ◽  
Water Molecule ◽  
Density Functional ◽  
Critical Concentration ◽  
Metal Organic Framework ◽  
Water Dimer ◽  
Hydroxyl Group ◽  
Water Molecules ◽  
Generalized Gradient ◽  
Functional Theory

We use density functional theory meta-generalized gradient approximation TPSS + D3(BJ) + U + J calculations to investigate the energetics and geometry of water molecules in the flexible metal-organic framework material Materials of Institut Lavoisier (MIL)-53(Cr) as a function of cell volume. The critical concentration of water to cause the transition from the large pore (lp) to the narrow pore (np) structure is estimated to be about 0.13 water molecule per Cr. At a concentration x = 1 water molecule per Cr, the zero-temperature np and lp configurations each have a hydrogen bond between the H of each framework hydroxyl group and water oxygen (OW). At intermediate volumes, water dimer-like configurations are observed. A concentration x = 1.25 leads to hydrogen bonding between water molecules in the np phase that is absent for x = 1. Our results suggest possible mechanisms for pore closing in hydrated MIL-53(Cr).

Internal dynamics of cyclohexanol and the cyclohexanol–water adduct

2019 ◽  
Vol 21 (7) ◽  
pp. 3676-3682 ◽  
Author(s):  
Marcos Juanes ◽  
Weixing Li ◽  
Lorenzo Spada ◽  
Luca Evangelisti ◽  
Alberto Lesarri ◽  
...  
Keyword(s):  
Water Molecule ◽  
Water Dimer ◽  
Hydroxyl Group ◽  
Rotational Spectrum ◽  
Internal Dynamics

Two for a tango: the rotational spectrum of a cyclohexanol–water dimer evidences a concerted motion of the water molecule and the hydroxyl group of the ring.

Atomic Charges of the Water Molecule and the Water Dimer

1998 ◽  
Vol 102 (39) ◽  
pp. 7686-7691 ◽  
Author(s):  
Per-Olof Åstrand ◽  
Kenneth Ruud ◽  
Kurt V. Mikkelsen ◽  
Trygve Helgaker
Keyword(s):  
Water Molecule ◽  
Water Dimer ◽  
Atomic Charges

Reconstruction of Two-Dimensional Projections of GP 32*I

1981 ◽  
Vol 39 ◽  
pp. 38-39
Author(s):  
H.A. Cohen ◽  
W. Chiu ◽  
J. Hosoda
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Uranyl Acetate ◽  
Distilled Water ◽  
Acetate Solution ◽  
Two Dimensional ◽  
Parent Molecule ◽  
T4 Bacteriophage ◽  
Electron Imaging ◽  
Better Than

GP 32 (molecular weight 35000) is a T4 bacteriophage protein that destabilizes the DNA helix. The fragment GP32*I (77% of the total weight), which destabilizes helices better than does the parent molecule, crystallizes as platelets thin enough for electron diffraction and electron imaging. In this paper we discuss the structure of this protein as revealed in images reconstructed from stained and unstained crystals.Crystals were prepared as previously described. Crystals for electron microscopy were pelleted from the buffer suspension, washed in distilled water, and resuspended in 1% glucose. Two lambda droplets were placed on grids over freshly evaporated carbon, allowed to sit for five minutes, and then were drained. Stained crystals were prepared the same way, except that prior to draining the droplet, two lambda of aqueous 1% uranyl acetate solution were applied for 20 seconds. Micrographs were produced using less than 2 e/Å2 for unstained crystals or less than 8 e/Å2 for stained crystals.

Identification of Fibrinogen Derivatives in Plasma Samples

1972 ◽  
Vol 27 (03) ◽  
pp. 610-618 ◽  
Author(s):  
H Graeff ◽  
R von Hugo
Keyword(s):  
Molecular Weight ◽  
Gel Electrophoresis ◽  
Gel Chromatography ◽  
Agarose Gel ◽  
Plasma Samples ◽  
Methodological Study ◽  
Parent Molecule ◽  
Electrophoretic Mobilities ◽  
Fibrin Monomer

SummaryThe observation of fibrinogen derivatives with a molecular weight higher than the parent molecule in human cases of DIC initiated the present methodological study. These derivatives were identified by the following methods : 2.5 M β-alanine precipitation of the plasma samples, PAA gel electrophoresis, intra gel immunoprecipitation and agarose gel chromatography. In the plasma of a patient with severe eclampsia and laboratory signs of DIC two derivatives with a molecular weight higher than that of fibrinogen were identified according to their relative electrophoretic mobilities: 0.18 and 0.28 × 10−5 cm2/V × sec (fibrinogen: 0.43 × 10−5 cm2/V × sec). Electrophoretic studies in the presence of 5 M urea indicated that the 0.28 derivative is a complex probably formed by fibrinogen and a fibrin monomer.

A Novel Chimaeric Derivative of Saruplase, rscu-PA-40kDA/Hir, Binds to Thrombin and Exerts Thrombus-specific Fibrinolysis in Arterial and Venous Thrombosis in Dogs

1997 ◽  
Vol 77 (03) ◽  
pp. 535-539 ◽  
Author(s):  
J Schneider ◽  
R Hauser ◽  
H-H Hennies ◽  
J Korioth ◽  
G Steffens ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Plasma Levels ◽  
Time Course ◽  
Bolus Injection ◽  
Specific Activity ◽  
Intravenous Bolus ◽  
Protease Domain ◽  
Parent Molecule ◽  
Significant Prolongation ◽  
Inhibitory Domain

SummaryThe chimaeric molecule rscu-PA-40kDA/Hir (M23) comprises the kringle and protease domain of saruplase (rscu-PA) and a thrombin inhibitory domain fused to the C-terminus of the protease domain. The 27 amino acid long thrombin inhibitory domain contains a sequence directed to the active site of thrombin and a fragment from the C-terminal region of hirudin. 125I-radiolabelled M23 (0.03 µM) bound to thrombin that was immobilised onto CNBr-activated sepharose beads. Unlabelled M23 (0.01-10 |xM) and hirudin (0.001-10 µµM) concentra-tion-dependently displaced 125I-M23 from its binding to thrombin. Saruplase (up to 10 (iM) did not influence the thrombin binding of M23. The fibrinolytic properties of M23 and saruplase were compared in anaesthetized dogs with femoral artery and saphenous vein thrombosis. Under concomitant heparinization, the intravenous bolus injections of 1 mg/kg M23 or saruplase induced reperfusion of thrombotically occluded femoral arteries in 4 out of 5 treated animals in each case. There was one reocclusion in the M23-treated group. Time to reperfusion (23 ± 4 vs 25 ± 11 min) and maximal height of reperfusion blood flow (98 ± 21 vs 108 ± 15 % of baseline flow) did not differ significantly between the treatment groups. The time course of the lysis of incorporated 125I-fibrin radioactivity in thrombosed saphenous veins was similar after bolus injections of M23 and saruplase. The maximal dissolution of 125I-fibrin in the venous thrombosis model was 91 ± 1 % in M23-and 88 ± 5 % in saruplase-treated animals. Plasma levels of fibrinogen were not influenced and a2-antiplasmin levels were slightly reduced (-27 ± 3 %) after bolus injection of M23. In contrast, bolus injection of saruplase was accompanied by a significant decrease of fibrinogen (-55 ± 19 %) and a2-antiplasmin (-75 ±11%) plasma levels. Template bleeding times virtually did not differ before (2.8 ± 0.3 min) and 60 min after bolus injection of M23 (3.1 ± 0.3 min), whereas treatment with saruplase resulted in a significant prolongation of template bleeding time from 2.6 ± 0.2 min to 28 ± 13 min. It is concluded that the saruplase derivative M23, while inducing equieffective thrombolysis after intravenous bolus injection in dogs, causes much fewer haemostatic side effects than its parent molecule. The high thrombus-specific activity of M23 is tentatively attributed to its affinity to clot-bound thrombin.

THE ROTATIONAL SPECTRA OF CYANOACETYLENE DIMER, H-C-C-C-N ••• H-C-C-C-N

2016 ◽  
Author(s):  
Philip Davis ◽  
Stewart Novick ◽  
Stephen Kukolich ◽  
Adam Daly ◽  
Kexin Li ◽  
...  
Keyword(s):  
Rotational Spectra
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