Previous studies have confirmed that the beclin 1 complex plays a key role in the initial stage of autophagy and deregulated autophagy might involve in amyotrophic lateral sclerosis. However, the mechanism underlying ...Previous studies have confirmed that the beclin 1 complex plays a key role in the initial stage of autophagy and deregulated autophagy might involve in amyotrophic lateral sclerosis. However, the mechanism underlying altered autophagy associated with the beclin 1 complex remains un- clear. In this study, we transfected the Cu/Zn superoxide dismutase 1 G93A mutant protein into the motor neuron-like cell line NSC34 cultured in vitro. Western blotting and co-immunopre- cipitation showed that the Cu/Zn superoxide dismutase 1 G93A mutant enhanced the turnover of autophagic marker microtubule-associated protein light chain 3II （LC3Ⅱ） and stimulated the conversion of EGFP-LC3Ⅰ to EGFP-LC3Ⅱ, but had little influence on the binding capacity of the autophagy modulators ATG14L, rubicon, UVRAG, and hVps34 to beclin 1 during auto- phagosome formation. These results suggest that the amyotrophic lateral sclerosis-linked Cu/Zn superoxide dismutase I G93A mutant can upregulate autophagic activity in NSC34 cells, but that this does not markedly affect beclin 1 complex components.展开更多
This work confirms the new view of the initiation and propagation mechanism of the anionic polymerization previously proposed, based on the investigation of anionic bulk-polymerization of styrene and α-methyl styrene...This work confirms the new view of the initiation and propagation mechanism of the anionic polymerization previously proposed, based on the investigation of anionic bulk-polymerization of styrene and α-methyl styrene with the help of a self designed microflow device and characterized by GPC and in situ ^7Li NMR. It was found that n-BuLl tended to form the hexameric-aggregated structure and even to form the huge aggregated structure based on the former. These aggregations of initiators could directly initiate the anionic polymerization and form the su-pramolecule aggregations. The supramolecule aggregations inevitably blocked the diffusion of the monomers to the ion-pairs and resulted in a stationary-conversion platform. Then the aggregators were dissociated completely into equal binary-aggregated species, and the polymerization continued again rapidly before the termination. Tetrahy-drofuran （THF） acted as the electron donator, which could push the electron cloud to Li cation and make the aggre- gated ring of the active species rather loosened and facilitated the monomer to insert in. Therefore, a little THF can greatly promote the anionic polymerization. However, further addition of THF might block the channel between the ion-pairs and decrease the propagation rate. It was also found that the aggregated structure of the active species during the anionic polymerization only depends on the initiator aggregations which were formed before the polym-erization.展开更多
The geometries of tetraphenylporphyrin which is a kind of important porphyrin derivatives, and its N-protonated diacid are calculated with AM1 MO method under symmetry restriction. The configurational changes and thei...The geometries of tetraphenylporphyrin which is a kind of important porphyrin derivatives, and its N-protonated diacid are calculated with AM1 MO method under symmetry restriction. The configurational changes and their effects on molecular aggregation are discussed by means of structure analysis, charge population analysis and frontier orbital analysis.展开更多
基金supported in part by an Oversea Study Fellowship from the China Scholarship Council,No.2008630089
文摘Previous studies have confirmed that the beclin 1 complex plays a key role in the initial stage of autophagy and deregulated autophagy might involve in amyotrophic lateral sclerosis. However, the mechanism underlying altered autophagy associated with the beclin 1 complex remains un- clear. In this study, we transfected the Cu/Zn superoxide dismutase 1 G93A mutant protein into the motor neuron-like cell line NSC34 cultured in vitro. Western blotting and co-immunopre- cipitation showed that the Cu/Zn superoxide dismutase 1 G93A mutant enhanced the turnover of autophagic marker microtubule-associated protein light chain 3II （LC3Ⅱ） and stimulated the conversion of EGFP-LC3Ⅰ to EGFP-LC3Ⅱ, but had little influence on the binding capacity of the autophagy modulators ATG14L, rubicon, UVRAG, and hVps34 to beclin 1 during auto- phagosome formation. These results suggest that the amyotrophic lateral sclerosis-linked Cu/Zn superoxide dismutase I G93A mutant can upregulate autophagic activity in NSC34 cells, but that this does not markedly affect beclin 1 complex components.
基金Financial supports for this work from the Nature Science Foundation of China for the Major Program （No. 50933002）, the National High Technology Re-search and Development Program of China （863 Pro-gram, No. 2012AA040306） and Shanghai Leading Academic Discipline Project （No. B502） are gratefully acknowledged.
文摘This work confirms the new view of the initiation and propagation mechanism of the anionic polymerization previously proposed, based on the investigation of anionic bulk-polymerization of styrene and α-methyl styrene with the help of a self designed microflow device and characterized by GPC and in situ ^7Li NMR. It was found that n-BuLl tended to form the hexameric-aggregated structure and even to form the huge aggregated structure based on the former. These aggregations of initiators could directly initiate the anionic polymerization and form the su-pramolecule aggregations. The supramolecule aggregations inevitably blocked the diffusion of the monomers to the ion-pairs and resulted in a stationary-conversion platform. Then the aggregators were dissociated completely into equal binary-aggregated species, and the polymerization continued again rapidly before the termination. Tetrahy-drofuran （THF） acted as the electron donator, which could push the electron cloud to Li cation and make the aggre- gated ring of the active species rather loosened and facilitated the monomer to insert in. Therefore, a little THF can greatly promote the anionic polymerization. However, further addition of THF might block the channel between the ion-pairs and decrease the propagation rate. It was also found that the aggregated structure of the active species during the anionic polymerization only depends on the initiator aggregations which were formed before the polym-erization.
文摘The geometries of tetraphenylporphyrin which is a kind of important porphyrin derivatives, and its N-protonated diacid are calculated with AM1 MO method under symmetry restriction. The configurational changes and their effects on molecular aggregation are discussed by means of structure analysis, charge population analysis and frontier orbital analysis.
