A series of highly active Ni2P-Mo S2/γ-Al2O3 catalysts were prepared and characterized, the catalytic performance of which was evaluated through hydrodesulfurization of dibenzothiophene. The result indicated that whe...A series of highly active Ni2P-Mo S2/γ-Al2O3 catalysts were prepared and characterized, the catalytic performance of which was evaluated through hydrodesulfurization of dibenzothiophene. The result indicated that when the amount of Ni2 P was 4%, the catalyst showed a relatively high activity to provide a reliable reference for the hydrodesulfurization pathway in comparison with the conventional Ni Mo and Ni Mo P catalysts. The physicochemical properties of the catalysts were correlated with their catalytic activity and selectivity on hydrodesulfurization. The stacking number of active Mo S2 phases was important for influencing the hydrogenation activity.展开更多
Proteins are essential parts of living organisms and participate in virtually every process within cells. As the genomlc sequences for increasing number of organisms are completed, research into how proteins can perfo...Proteins are essential parts of living organisms and participate in virtually every process within cells. As the genomlc sequences for increasing number of organisms are completed, research into how proteins can perform such a variety of functions has become much more intensive because the value of the genomic sequences relies on the accuracy of understanding the encoded gene products. Although the static three-dimensional structures of many proteins are known, the functions of proteins are ulti- mately governed by their dynamic characteristics, including the folding process, conformational fluctuations, molecular mo- tions, and protein-ligand interactions. In this review, the physicochemical principles underlying these dynamic processes are discussed in depth based on the free energy landscape （FEL） theory. Questions of why and how proteins fold into their native conformational states, why proteins are inherently dynamic, and how their dynamic personalities govern protein functions are answered. This paper will contribute to the understanding of structure-function relationship of proteins in the post-genome era of life science research.展开更多
The HIV-1 gp120 exterior envelope glycoprotein undergoes a series of conformational rearrangements while sequentially interacting with the receptor CD4 and coreceptor CCR5 or CXCR4 on the surface of host cells to init...The HIV-1 gp120 exterior envelope glycoprotein undergoes a series of conformational rearrangements while sequentially interacting with the receptor CD4 and coreceptor CCR5 or CXCR4 on the surface of host cells to initiate virus entry. Both the crystal structures of the HIV-1 gp120 core bound by the CD4 and antigen 17b and the SIV gp120 core pre-bound by CD4 are known. Despite the wealth of knowledge on these static snapshots of molecular conformations,the details of molecular motions involved in conformational transition that are crucial to intervention remain elusive. We presented comprehensive comparative analyses of the dynamics behaviors of the gp120 in its CD4-complexed,CD4-free and CD4-unliganded states based on the homology models with modeled V3 and V4 loops by means of CONCOORD computer simulation to generate ensembles of feasible protein structures that were sub-sequently analysed by essential dynamics analyses to identify preferred concerted motions. The re-vealed collective fluctuations are dominated by complex modes of combinational motions of the rota-tion/twisting,flexing/closure,and shortness/elongation between or within the inner,outer,and bridg-ing-sheet domains,and these modes are related to the CD4 association and HIV neutralization avoid-ance. Further essential subspace overlap analyses were performed to quantitatively distinguish the preference for conformational transitions between the three states,revealing that the unliganded gp120 has a greater potential to translate its conformation into the conformational state adopted by the CD4-complexed gp120 than by the CD4-free gp120,whereas the CD4-free gp120 has a greater potential to translate its conformation into the unliganded state than the CD4-complexed gp120 does. These dynamics data of gp120 in its different conformations are helpful in understanding the relationship between the molecular motion/conformational transition and the function of gp120,and in gp120-structure-based subunit vaccine design.展开更多
A novel coronavirus has been identified as the causative agent of the severe acute respiratory syndrome(SARS). For all the SARS-CoV associated proteins derivatedfrom the SARS-CoV genome, the physiochemical propertiess...A novel coronavirus has been identified as the causative agent of the severe acute respiratory syndrome(SARS). For all the SARS-CoV associated proteins derivatedfrom the SARS-CoV genome, the physiochemical propertiessuch as the molecular weight, isoelectric point and extinction coefficient of each protein were calculated. Thetransmembrane segments and subcellular localization(SubLocation) prediction and conserved protein motifssearch against database were employed to analyze thefunction of SARS-CoV proteins. Also, the homology protein sequence alignment and evolutionary distance matrixcalculation between SARS-CoV associated proteins and the corresponding proteins of other coronaviruses wereemployed to identify the classification and phylogeneticrelationship between SARS-CoV and other coronaviruses.The results showed that SARS-CoV is a novel coronavirus which is different from any of the three previously knowngroups of coronviruses, but it is closer to BoCoV and MHV than to other coronaviruses. This study is in aid ofexperimental determination of SARS-CoV proteomics andthe development of antiviral vaccine.展开更多
基金financially supported by the Natural Science Foundation of Anhui Province(No.1408085QB44)the Natural Science Foundation of Educational Committee of Anhui Province(No.KJ2013B243)the Youth Foundation of Huaibei Normal University(2013xqz01)
文摘A series of highly active Ni2P-Mo S2/γ-Al2O3 catalysts were prepared and characterized, the catalytic performance of which was evaluated through hydrodesulfurization of dibenzothiophene. The result indicated that when the amount of Ni2 P was 4%, the catalyst showed a relatively high activity to provide a reliable reference for the hydrodesulfurization pathway in comparison with the conventional Ni Mo and Ni Mo P catalysts. The physicochemical properties of the catalysts were correlated with their catalytic activity and selectivity on hydrodesulfurization. The stacking number of active Mo S2 phases was important for influencing the hydrogenation activity.
基金supported by the National Natural Science Foundation of China(31370715,31160181,31360277,30860011)the National Basic Research Program of China(2013CB127500)+1 种基金the Program of Innovation Group of Yunnan Province(2011CI123)Foundation for Key Teacher in Yunnan University(XT412003)
文摘Proteins are essential parts of living organisms and participate in virtually every process within cells. As the genomlc sequences for increasing number of organisms are completed, research into how proteins can perform such a variety of functions has become much more intensive because the value of the genomic sequences relies on the accuracy of understanding the encoded gene products. Although the static three-dimensional structures of many proteins are known, the functions of proteins are ulti- mately governed by their dynamic characteristics, including the folding process, conformational fluctuations, molecular mo- tions, and protein-ligand interactions. In this review, the physicochemical principles underlying these dynamic processes are discussed in depth based on the free energy landscape （FEL） theory. Questions of why and how proteins fold into their native conformational states, why proteins are inherently dynamic, and how their dynamic personalities govern protein functions are answered. This paper will contribute to the understanding of structure-function relationship of proteins in the post-genome era of life science research.
基金Supported by the Yunnan University (Grant No. 2004Q013B)Yunnan Province (Grant No. 2006C008M)partially supported by open fund from the Laboratory for Conservation and Utilization of Bio-resources, Yunnan University, and Innova-tion Group Project from Yunnan University
文摘The HIV-1 gp120 exterior envelope glycoprotein undergoes a series of conformational rearrangements while sequentially interacting with the receptor CD4 and coreceptor CCR5 or CXCR4 on the surface of host cells to initiate virus entry. Both the crystal structures of the HIV-1 gp120 core bound by the CD4 and antigen 17b and the SIV gp120 core pre-bound by CD4 are known. Despite the wealth of knowledge on these static snapshots of molecular conformations,the details of molecular motions involved in conformational transition that are crucial to intervention remain elusive. We presented comprehensive comparative analyses of the dynamics behaviors of the gp120 in its CD4-complexed,CD4-free and CD4-unliganded states based on the homology models with modeled V3 and V4 loops by means of CONCOORD computer simulation to generate ensembles of feasible protein structures that were sub-sequently analysed by essential dynamics analyses to identify preferred concerted motions. The re-vealed collective fluctuations are dominated by complex modes of combinational motions of the rota-tion/twisting,flexing/closure,and shortness/elongation between or within the inner,outer,and bridg-ing-sheet domains,and these modes are related to the CD4 association and HIV neutralization avoid-ance. Further essential subspace overlap analyses were performed to quantitatively distinguish the preference for conformational transitions between the three states,revealing that the unliganded gp120 has a greater potential to translate its conformation into the conformational state adopted by the CD4-complexed gp120 than by the CD4-free gp120,whereas the CD4-free gp120 has a greater potential to translate its conformation into the unliganded state than the CD4-complexed gp120 does. These dynamics data of gp120 in its different conformations are helpful in understanding the relationship between the molecular motion/conformational transition and the function of gp120,and in gp120-structure-based subunit vaccine design.
文摘A novel coronavirus has been identified as the causative agent of the severe acute respiratory syndrome(SARS). For all the SARS-CoV associated proteins derivatedfrom the SARS-CoV genome, the physiochemical propertiessuch as the molecular weight, isoelectric point and extinction coefficient of each protein were calculated. Thetransmembrane segments and subcellular localization(SubLocation) prediction and conserved protein motifssearch against database were employed to analyze thefunction of SARS-CoV proteins. Also, the homology protein sequence alignment and evolutionary distance matrixcalculation between SARS-CoV associated proteins and the corresponding proteins of other coronaviruses wereemployed to identify the classification and phylogeneticrelationship between SARS-CoV and other coronaviruses.The results showed that SARS-CoV is a novel coronavirus which is different from any of the three previously knowngroups of coronviruses, but it is closer to BoCoV and MHV than to other coronaviruses. This study is in aid ofexperimental determination of SARS-CoV proteomics andthe development of antiviral vaccine.
