We have previously shown that the diphtheria toxin variant CRM 197 （cross-reacting material 197） can be overexpressed in Escherichia coli at high levels, yielding insoluble aggregates, which were solubilized using u...We have previously shown that the diphtheria toxin variant CRM 197 （cross-reacting material 197） can be overexpressed in Escherichia coli at high levels, yielding insoluble aggregates, which were solubilized using urea. This study reports a comparison of three matrices suitable for the purification and refolding of recombinant CRM197 by metal-chelating affinity chromatography, Moreover, we show that refolded CRM197 features enzymatic activity.展开更多
A series of genistein-polyamine conjugates(4a–4h) were designed, synthesized and evaluated as multi-functional anti-Alzheimer agents. The results showed that these compounds had significant cholinesterases(Ch Es) inh...A series of genistein-polyamine conjugates(4a–4h) were designed, synthesized and evaluated as multi-functional anti-Alzheimer agents. The results showed that these compounds had significant cholinesterases(Ch Es) inhibitory activity. Compound 4b exhibited the strongest inhibition to acetylcholinesterase(ACh E) with an IC_(50) value of 2.75 μmol/L, which was better than that of rivastigmine(5.60 μmol/L). Lineweaver–Burk plot and molecular modeling study showed that compound 4b targeted both the catalytic active site(CAS) and the peripheral anionic site(PAS) of ACh E. Besides, compound 4b showed potent metal-chelating ability. In addition, it was found that 4a–4h did not affect Hep G-2 cell viability at the concentration of 10 μmol/L.展开更多
文摘We have previously shown that the diphtheria toxin variant CRM 197 （cross-reacting material 197） can be overexpressed in Escherichia coli at high levels, yielding insoluble aggregates, which were solubilized using urea. This study reports a comparison of three matrices suitable for the purification and refolding of recombinant CRM197 by metal-chelating affinity chromatography, Moreover, we show that refolded CRM197 features enzymatic activity.
基金the National Natural Science Foundation of China (Nos. 21172053 and 21302041)the China Postdoctoral Science Foundation (No. 2012M521391)+1 种基金the Postdoctoral Science Foundation of Henan Province (No. 2011015)the Foundation of Henan Educational Committee (No. 14A350008)
文摘A series of genistein-polyamine conjugates(4a–4h) were designed, synthesized and evaluated as multi-functional anti-Alzheimer agents. The results showed that these compounds had significant cholinesterases(Ch Es) inhibitory activity. Compound 4b exhibited the strongest inhibition to acetylcholinesterase(ACh E) with an IC_(50) value of 2.75 μmol/L, which was better than that of rivastigmine(5.60 μmol/L). Lineweaver–Burk plot and molecular modeling study showed that compound 4b targeted both the catalytic active site(CAS) and the peripheral anionic site(PAS) of ACh E. Besides, compound 4b showed potent metal-chelating ability. In addition, it was found that 4a–4h did not affect Hep G-2 cell viability at the concentration of 10 μmol/L.
