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951.
The success of positron emission tomography (PET) in personalised medicine and drug development requires radioisotopes that provide high quality images and flexible chemistry for a broad application. 64Cu is arguably one of the most suitable PET isotopes for imaging with the evolving target agents, but there are not many appropriate chelating agents for 64Cu and this has limited its wider application. The bi-functional chelator, SarAr is known to bind 64Cu2+ quantitatively (i.e. one metal per ligand present) and rapidly (<2 min) at 10(-6) M over a range of pH (4-9). In this paper the conjugation of SarAr to the whole and fragmented antibody is described. Conjugation of the SarAr to the protein does not impair its coordination of the 64Cu. It complexes the 64Cu2+ rapidly, quantitatively and essentially irreversibly at pH 5. Animal studies show that the 64Cu-SarAr-immunoconjugates maintain their specificity for the target and are stable in vivo. Also, SarAr is a platform technology, is easy to use in a kit formulation and is readily adaptable for the wider application in 64Cu PET imaging. 相似文献
952.
Amadei A D'Alessandro M Paci M Di Nola A Aschi M 《The journal of physical chemistry. B》2006,110(14):7538-7544
In this paper, we investigate the effects of a point mutation on the enzymatic activity of copper-zinc superoxide dismutase, which we recently studied in detail by means of a theoretical-computational procedure. Comparison of the reactivity of the initial catalytic steps in this mutant (G93A mutation far from the active site) with our previous data, reveals the beautiful mechanical-dynamical architecture of the enzyme, altered by such an apparently irrelevant mutation. Finally, our results suggest a possible atomic-molecular-based explanation for the mutant-pathology correlation, in line with the most recent experimental data. 相似文献
953.
Ulmschneider JP Ulmschneider MB Di Nola A 《The journal of physical chemistry. B》2006,110(33):16733-16742
An efficient Monte Carlo (MC) algorithm including concerted rotations is directly compared to molecular dynamics (MD) in all-atom statistical mechanics folding simulations of small polypeptides. The previously reported algorithm "concerted rotations with flexible bond angles" (CRA) has been shown to successfully locate the native state of small polypeptides. In this study, the folding of three small polypeptides (trpzip2/H1/Trp-cage) is investigated using MC and MD, for a combined sampling time of approximately 10(11) MC configurations and 8 micros, respectively. Both methods successfully locate the experimentally determined native states of the three systems, but they do so at different speed, with 2-2.5 times faster folding of the MC runs. The comparison reveals that thermodynamic and dynamic properties can reliably be obtained by both and that results from folding simulations do not depend on the algorithm used. Similar to previous comparisons of MC and MD, it is found that one MD integration step of 2 fs corresponds to one MC scan, revealing the good sampling of MC. The simplicity and efficiency of the MC method will enable its future use in folding studies involving larger systems and the combination with replica exchange algorithms. 相似文献
954.
Wang D Villa A Porta F Su D Prati L 《Chemical communications (Cambridge, England)》2006,(18):1956-1958
Single phase bimetallic Au/Pd catalyst was prepared and characterised by TEM techniques. The high activity in the selective liquid phase oxidation of glycerol towards glycerate is unambiguously attributed to the synergistic effect of alloy. 相似文献
955.
Di J Yao K Han W Bi S 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2006,65(3-4):896-900
The interaction of superoxide dismutase (SOD) with aluminum (Al) ions was investigated by cyclic voltammetry, fluorescence spectroscopy and synchronous fluorescence spectroscopy. The electrochemical activity of the SOD enzyme electrode was inhibited irreversibly by the addition of Al. Meanwhile, the static fluorescence quenching mechanism further revealed the existing of molecular complex of SOD with Al(3+). The association constant was obtained from Lineweaver-Burk plot. The experimental results of voltammetry and fluorescence spectroscopy indicated that the conformation of SOD molecule was altered by the formation of Al-SOD complex. It may influence the activity of SOD enzyme since the optimum action of SOD depends upon a particular configuration of electrostatic charges in the enzyme molecule. 相似文献
956.
Addamo M Bellardita M Di Paola A Palmisano L 《Chemical communications (Cambridge, England)》2006,(47):4943-4945
Photoactive films consisting of pure anatase, brookite or rutile TiO2 were prepared by dip coating from water dispersions obtained by using TiCl4 as the precursor under similar mild experimental conditions. 相似文献
957.
Highly selective enzymatic reductions of aldehydes to the corresponding alcohols was performed using an E. coli JM109 whole cell biocatalyst. A selective enzymatic method for the reduction of aldehydes could provide an eco-compatible alternative to chemical methods. The simplicity, fairly wide scope and the very high observed chemoselectivity of this approach are its most unique features. 相似文献
958.
959.
960.
Riekel C Burghammer M Davies RJ Di Cola E König C Lemke HT Putaux JL Schöder S 《Journal of synchrotron radiation》2010,17(6):743-750
X-ray radiation damage propagation is explored for hydrated starch granules in order to reduce the step resolution in raster-microdiffraction experiments to the nanometre range. Radiation damage was induced by synchrotron radiation microbeams of 5, 1 and 0.3?μm size with ~0.1?nm wavelength in B-type potato, Canna edulis and Phajus grandifolius starch granules. A total loss of crystallinity of granules immersed in water was found at a dose of ~1.3?photons?nm(-3). The temperature dependence of radiation damage suggests that primary radiation damage prevails up to about 120?K while secondary radiation damage becomes effective at higher temperatures. Primary radiation damage remains confined to the beam track at 100?K. Propagation of radiation damage beyond the beam track at room temperature is assumed to be due to reactive species generated principally by water radiolysis induced by photoelectrons. By careful dose selection during data collection, raster scans with 500?nm step-resolution could be performed for granules immersed in water. 相似文献