title: Catalytic effect of ferricyanide between myoglobin and luminol and effect of temperature.
abstract: Specific catalytic oxidation of oxymyoglobin (MbO(2)) and luminol by ferricyanide was studied in a flow-injection system. MbO(2) in different redox states (ferric and ferrous) was oxidized to Mb(Fe(III)) by ferricyanide, and then specific binding of the ferrocyanide anion to Mb(Fe(III)) to the His 119 (GH1) region accelerated the electron transfer between Mb(Fe(III)) and luminol, which produced a chemiluminescence (CL) signal at 425 nm. The increased CL emission was correlated with the myoglobin concentration in the range 0.16-7.5 microg/mL. Thermogravimetry and differential scanning calorimetry were used to investigate the temperature effects on this reaction. The results showed that the CL intensity in the presence of myoglobin changed considerably with heating in the range 15-50 degrees C, and the maximal CL intensity was observed at 40 degrees C, corresponding to the glass transition temperature of myoglobin. The effect of different ligands and interferences were also studied.
authors.affiliation: School of Chemical Engineering, Northwest University, Xi'an 710069, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Gao
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Liu
authors.forename: Zhenghua
authors.initials: Z
authors.lastname: Song
mesh_terms: D002384:Catalysis; D005292:Ferricyanides / Q000737:chemistry*; D017022:Flow Injection Analysis; D008163:Luminescent Measurements; D008165:Luminol / Q000737:chemistry*; D009211:Myoglobin / Q000737:chemistry*; D010084:Oxidation-Reduction; D013696:Temperature
chemical_list: D005292:Ferricyanides; D009211:Myoglobin; D008165:Luminol