tailieunhanh - Báo cáo khoa học: A superoxide dismutase–human hemoglobin fusion protein showing enhanced antioxidative properties

Much of the toxicity of Hb has been linked to its redox activity; Hb may generate reactive oxygen species, such as the superoxide anion. Superoxide is intrinsically toxic, and superoxide dismutase (SOD) provides important cellular protection. However, if the Hb molecule is located outside the red blood cell, the normal protection systems involving SOD and catalase are no longer closely associated with it, exposing Hb and its cellular surround | ỊFEBS Journal A superoxide dismutase-human hemoglobin fusion protein showing enhanced antioxidative properties Marie Grey1 Sakda Yainoy1 2 Virapong Prachayasittikul2 and Leif Bulow1 1 Department of Pure and Applied Biochemistry Centre for Chemistry and ChemicalEngineering Lund University Sweden 2 Department of ClinicalMicrobiology Faculty of MedicalTechnology MahidolUniversity Bangkok Thailand Keywords antioxidation fusion protein hemoglobin superoxide dismutase Correspondence L. Bulow Department of Pure and Applied Biochemistry Centre for Chemistry and ChemicalEngineering Lund University . Box 124 SE-21100 Lund Sweden Fax 46 46 222 4611 Tel 46 46 222 9594 E-mail Received 13 May 2009 revised 27 July 2009 accepted 24 August 2009 doi Much of the toxicity of Hb has been linked to its redox activity Hb may generate reactive oxygen species such as the superoxide anion. Superoxide is intrinsically toxic and superoxide dismutase SOD provides important cellular protection. However if the Hb molecule is located outside the red blood cell the normal protection systems involving SOD and catalase are no longer closely associated with it exposing Hb and its cellular surroundings to oxidative damage. In order to produce less toxic Hb molecules we have explored gene fusion to obtain homogeneous SOD-Hb conjugates. The chimeric protein was generated by coexpressing the human Hb a-chain manganese SOD gene together with the b-chain gene in Escherichia coli. We show that the engineered SOD-Hb fusion protein retains the oxygen-binding capacity and moreover decreases cytotoxic ferrylHb HbFe4 formation when challenged with superoxide radicals. The SOD-Hb fusion protein also exhibits a 44 lower autoxidation rate and higher thermal stability than Hb alone. Introduction The toxicity of Hb outside of its natural protective red blood cell environment has been linked partly to the redox activity of the Hb molecule. Consequently Hb .

• Báo cáo khoa học
• scientific reports
• thesis report
• medical report
• Much of the toxicity of Hb has been linked to its redox activity; Hb may generate reactive oxygen species
• such as the superoxide anion
• Superoxide is intrinsically toxic
• and superoxide dismutase (SOD) provides important cellular protection
• However
• if the Hb molecule is located outside the red blood cell
• the normal protection systems involving SOD and catalase are no longer closely associated with it
• exposing Hb and its cellular surround