Three solid organic peroxides, benzoyl peroxide (BPO), dicumyl peroxide (DCP) and cyclohexanone peroxide (CCP) were tested by using simultaneous TG-DSC analyzer (SDT Q600) with small sample mass, and the thermal data ...Three solid organic peroxides, benzoyl peroxide (BPO), dicumyl peroxide (DCP) and cyclohexanone peroxide (CCP) were tested by using simultaneous TG-DSC analyzer (SDT Q600) with small sample mass, and the thermal data obtained from different scanning rate were analyzed by the Popescu multiple scanning rate method for the first time.Then, the values of self-accelerating decomposition temperature (SADT) of 25 kg standard package were computed according to the thermal explosion theory.The results showed that the values of activation energy and pre-exponential factor of these three solid organic peroxides by using the Popescu multiple scanning rate method were more precise and more credible than that by using the single scanning rate method.Based on correct calculation of these kinetic parameters, SADT can be accurately safely, easily, quickly evaluated with thermodynamic parameters based on thermal explosion theory.展开更多
Dichloromethane(DCM)dehalogenase stands as a crucial enzyme implicated in the degradation of methylene chloride across diverse environmental and biological contexts.However,the unbinding pathways of ligands from DCM d...Dichloromethane(DCM)dehalogenase stands as a crucial enzyme implicated in the degradation of methylene chloride across diverse environmental and biological contexts.However,the unbinding pathways of ligands from DCM dehalogenase remain unexplored.In order to gain a deeper understanding of the binding sites and dissociation pathways of dichloromethane(DCM)and glutathione(GSH)from the DCM dehalogenase,random accelerated molecular dynamics(RAMD)simulations were performed,in which DCM and GSH were forced to leave the active site.The protein structure was predicted using Alphafold2,and the conformations of GSH and DCM in the binding pocket were predicted by docking.A long equilibrium simulation was conducted to validate the structure of the complex.The results show that GSH is most commonly observed in three main pathways,one of which is more important than the other two.In addition,DCM was observed to escape along a unique pathway.The key residues and protein helices of each pathway were identified.The results can provide a theoretical foundation for the subsequent dissociation mechanism of DCM dehalogenase.展开更多
文摘Three solid organic peroxides, benzoyl peroxide (BPO), dicumyl peroxide (DCP) and cyclohexanone peroxide (CCP) were tested by using simultaneous TG-DSC analyzer (SDT Q600) with small sample mass, and the thermal data obtained from different scanning rate were analyzed by the Popescu multiple scanning rate method for the first time.Then, the values of self-accelerating decomposition temperature (SADT) of 25 kg standard package were computed according to the thermal explosion theory.The results showed that the values of activation energy and pre-exponential factor of these three solid organic peroxides by using the Popescu multiple scanning rate method were more precise and more credible than that by using the single scanning rate method.Based on correct calculation of these kinetic parameters, SADT can be accurately safely, easily, quickly evaluated with thermodynamic parameters based on thermal explosion theory.
基金National Natural Science Foundation of China(22073030)the Oriental Scholars of Shanghai Universities。
文摘Dichloromethane(DCM)dehalogenase stands as a crucial enzyme implicated in the degradation of methylene chloride across diverse environmental and biological contexts.However,the unbinding pathways of ligands from DCM dehalogenase remain unexplored.In order to gain a deeper understanding of the binding sites and dissociation pathways of dichloromethane(DCM)and glutathione(GSH)from the DCM dehalogenase,random accelerated molecular dynamics(RAMD)simulations were performed,in which DCM and GSH were forced to leave the active site.The protein structure was predicted using Alphafold2,and the conformations of GSH and DCM in the binding pocket were predicted by docking.A long equilibrium simulation was conducted to validate the structure of the complex.The results show that GSH is most commonly observed in three main pathways,one of which is more important than the other two.In addition,DCM was observed to escape along a unique pathway.The key residues and protein helices of each pathway were identified.The results can provide a theoretical foundation for the subsequent dissociation mechanism of DCM dehalogenase.
