Aspergillus flavus causes serious disease on important agriculture crops, and its secondary metabolic products-aflatoxins are most potent toxin and carcinogen for animal and human, Structural and functional studies of...Aspergillus flavus causes serious disease on important agriculture crops, and its secondary metabolic products-aflatoxins are most potent toxin and carcinogen for animal and human, Structural and functional studies ofA. flavus proteins may provide insights into the identification of potential therapeutic targets and prevention of damage caused by A. flavus. Here, we report the expression, purification, crystallization and preliminary crystallographic analysis of NDK protein from A. flavus. The NDK protein was expressed in E. coli and purified by using a series of chromatographic methods to 〉98% purity. The recombinant protein was crystallized and the crystals diffracted to 2.4 A^° resolution. The crystal of NDK is in space group of C121 with a = 190.84, b = 169.47, c = 146.94 A^°. Preliminary data analysis indicated that the NDK molecule assembles into a multimer in the asymmetric unit.展开更多
The effect of nucleoside diphosphate kinase (NDPK) on the activrty of guanine nucleotide regulatory protein (G-protein) mediated phospholipase C(PLC) and on the [35S]GTPTτS binding of G-protein was investigated in th...The effect of nucleoside diphosphate kinase (NDPK) on the activrty of guanine nucleotide regulatory protein (G-protein) mediated phospholipase C(PLC) and on the [35S]GTPTτS binding of G-protein was investigated in this work in order to demonstrate the mechanism behind the regulation of G-protein and its effector PLC by NDPK. The stimulation of PLC in turkey erythrocyte membrane by both GTP and GTPτS indicated that the PLC stimulation was mediated by G-protein. NDPK alone stimulated PLC activity. as well as the stimulation in the presence of GTP and GDP, in a dose-dependent manner. However. NDPK inhibited GTPτS-stimulated PLC. Furthermore, NDPK inhibited [35S]GTPτS binding of purified Gi-protein in a non-competitive manner. A hypothesis implying an important role of direct interaction of G-protein and NDPK in the regulation of their functions is suggested and discussed.展开更多
Human Nm23 family consists of eight gene products that have been implicated in cellular differentiation,development and apoptosis,as well as oncogenesis and tumor metastasis.The protein products of Nm23 are nucleoside...Human Nm23 family consists of eight gene products that have been implicated in cellular differentiation,development and apoptosis,as well as oncogenesis and tumor metastasis.The protein products of Nm23 are nucleoside diphosphate kinases(NDPKs),the key metabolic enzymes that catalyze the synthesis of nucleoside triphosphates(NTP) by transfer of the terminal phosphate between NDP and NTP.Recent investigations are focused on the extraordinary pleiotropy and its mechanism of Nm23/NDPK.In this article,we review the recent progress in studies of the mechanism of Nm23/NDPK as metastasis suppressors,and other bioactivities of NDPK out of phosphate transfer enzyme,as well as the character of NDPK’s quaternary structure and the relation between its structure and function.In addition to these,the potential applications of NDPK as an enhancer of antiviral drugs or Nm23 as a drug target were also described.Findings herein summarized provide new and intriguing suggestions for a more extensive understanding of the biological functions of the star molecule,Nm23/NDPK.展开更多
基金supported by National 973 Program(No.2013CB127802)of Ministry of Science and Technology of Chinathe National Natural Science Foundation of China(Nos.31172297 and 31400100)
文摘Aspergillus flavus causes serious disease on important agriculture crops, and its secondary metabolic products-aflatoxins are most potent toxin and carcinogen for animal and human, Structural and functional studies ofA. flavus proteins may provide insights into the identification of potential therapeutic targets and prevention of damage caused by A. flavus. Here, we report the expression, purification, crystallization and preliminary crystallographic analysis of NDK protein from A. flavus. The NDK protein was expressed in E. coli and purified by using a series of chromatographic methods to 〉98% purity. The recombinant protein was crystallized and the crystals diffracted to 2.4 A^° resolution. The crystal of NDK is in space group of C121 with a = 190.84, b = 169.47, c = 146.94 A^°. Preliminary data analysis indicated that the NDK molecule assembles into a multimer in the asymmetric unit.
文摘The effect of nucleoside diphosphate kinase (NDPK) on the activrty of guanine nucleotide regulatory protein (G-protein) mediated phospholipase C(PLC) and on the [35S]GTPTτS binding of G-protein was investigated in this work in order to demonstrate the mechanism behind the regulation of G-protein and its effector PLC by NDPK. The stimulation of PLC in turkey erythrocyte membrane by both GTP and GTPτS indicated that the PLC stimulation was mediated by G-protein. NDPK alone stimulated PLC activity. as well as the stimulation in the presence of GTP and GDP, in a dose-dependent manner. However. NDPK inhibited GTPτS-stimulated PLC. Furthermore, NDPK inhibited [35S]GTPτS binding of purified Gi-protein in a non-competitive manner. A hypothesis implying an important role of direct interaction of G-protein and NDPK in the regulation of their functions is suggested and discussed.
文摘Human Nm23 family consists of eight gene products that have been implicated in cellular differentiation,development and apoptosis,as well as oncogenesis and tumor metastasis.The protein products of Nm23 are nucleoside diphosphate kinases(NDPKs),the key metabolic enzymes that catalyze the synthesis of nucleoside triphosphates(NTP) by transfer of the terminal phosphate between NDP and NTP.Recent investigations are focused on the extraordinary pleiotropy and its mechanism of Nm23/NDPK.In this article,we review the recent progress in studies of the mechanism of Nm23/NDPK as metastasis suppressors,and other bioactivities of NDPK out of phosphate transfer enzyme,as well as the character of NDPK’s quaternary structure and the relation between its structure and function.In addition to these,the potential applications of NDPK as an enhancer of antiviral drugs or Nm23 as a drug target were also described.Findings herein summarized provide new and intriguing suggestions for a more extensive understanding of the biological functions of the star molecule,Nm23/NDPK.