Soluble guanylate cyclase（sGC） is a critical heme-containing enzyme involved in NO signaling.The dimerization of sGC subunits is necessary for its bioactivity and its mechanism is a striking and an indistinct issue....Soluble guanylate cyclase（sGC） is a critical heme-containing enzyme involved in NO signaling.The dimerization of sGC subunits is necessary for its bioactivity and its mechanism is a striking and an indistinct issue.The roles of heme domain cysteines of the sGC on the dimerization and heme binding were investigated herein.The site-directed mutations of three conserved cysteines（C78A,C122A and C174S） were studied systematically and the three mutants were characterized by gel filtration analysis,UV-vis spectroscopy and heme transfer examination.Cys78 was involved in heme binding but not referred to the dimerization,while Cys174 was demonstrated to be involved in the homodimerization.These results provide new insights into the cysteine-related dimerization regulation of sGC.展开更多
Cytotoxicity of Aft with redox active metals in neuronal cells has been implicated in the progression of Alzheimer＇s disease （AD）. Zn7MT-3 protects cell against AβCu2＋ toxicity. The roles of single domain protei...Cytotoxicity of Aft with redox active metals in neuronal cells has been implicated in the progression of Alzheimer＇s disease （AD）. Zn7MT-3 protects cell against AβCu2＋ toxicity. The roles of single domain proteins （α/β） and α-β domain-domain interaction of ZnTMT-3 in its anti-Aβ1-42-Cu2＋ toxicity activity were investigated herein. Aβ1-42 and four mutants of human MT3 （α/β domain, β（MT3）--α（MT1） and △31-34） were prepared and characterized. Aβ1-42-Cu2＋ induced hydroxyl radical and ROS production with/without Zn-MTs were measured by fluorescence spectroscopy and DCFH-DA in living cells, respectively. These results indicate that the two domains form a co-operative unit and each of them is indispensable in conducting its bioactivity.展开更多
基金supported partly by Shanghai Pujiang Talent Project (No.:08PJ14017)the National Natural Science Foundation of China (Nos.:20771029 and 91013001)Shanghai Leading Academic Discipline Project (No. B108)
文摘Soluble guanylate cyclase（sGC） is a critical heme-containing enzyme involved in NO signaling.The dimerization of sGC subunits is necessary for its bioactivity and its mechanism is a striking and an indistinct issue.The roles of heme domain cysteines of the sGC on the dimerization and heme binding were investigated herein.The site-directed mutations of three conserved cysteines（C78A,C122A and C174S） were studied systematically and the three mutants were characterized by gel filtration analysis,UV-vis spectroscopy and heme transfer examination.Cys78 was involved in heme binding but not referred to the dimerization,while Cys174 was demonstrated to be involved in the homodimerization.These results provide new insights into the cysteine-related dimerization regulation of sGC.
基金supported partly by the National Natural Science Foundation of ChinaShanghai Leading Academic Discipline Project(NoB108)PhD program of the Education Ministry of China(No20100071110011)
文摘Cytotoxicity of Aft with redox active metals in neuronal cells has been implicated in the progression of Alzheimer＇s disease （AD）. Zn7MT-3 protects cell against AβCu2＋ toxicity. The roles of single domain proteins （α/β） and α-β domain-domain interaction of ZnTMT-3 in its anti-Aβ1-42-Cu2＋ toxicity activity were investigated herein. Aβ1-42 and four mutants of human MT3 （α/β domain, β（MT3）--α（MT1） and △31-34） were prepared and characterized. Aβ1-42-Cu2＋ induced hydroxyl radical and ROS production with/without Zn-MTs were measured by fluorescence spectroscopy and DCFH-DA in living cells, respectively. These results indicate that the two domains form a co-operative unit and each of them is indispensable in conducting its bioactivity.
