Spectral and kinetic studies on the interaction between oxyhaemoglobin and peroxynitrite: a comparison with hydrogen peroxide.
Interaction between oxyhaemoglobin and peroxynitrite was studied using stopped-flow rapid-scan spectrophotometry. The influence of pH, peroxynitrite concentration and temperature on the pseudo-first-order rate constants was studied and the activation energy calculated. The kinetic curve for the oxyhaemoglobin-peroxynitrite reaction showed that a fast reaction occurred in the initial seconds, followed by a slow process of decrease in absorbance. The biphasic reaction kinetics of oxyhaemoglobin with peroxynitrite or hydrogen peroxide demonstrated the existence of an intermediary species. For the first time a rapid-scan stopped-flow spectrophotometry study is presented, yielding spectral and kinetic data of the reaction.
Wang
Rui-yong
RY
Key Laboratory of MOE for Developmental Biology, College of Life Sciences, Wuhan University, Wuhan 430072, People's Republic of China. rywang97@163.com
Ji
Mi-na
MN
Cai
Ru-xiu
RX
Lu
Ying-tang
YT
D000818:Animals; D002417:Cattle; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007700:Kinetics; D010084:Oxidation-Reduction; D010108:Oxyhemoglobins / Q000737:chemistry*; D030421:Peroxynitrous Acid / Q000737:chemistry*; D010777:Photochemistry; D013057:Spectrum Analysis
D010108:Oxyhemoglobins; D030421:Peroxynitrous Acid; D006861:Hydrogen Peroxide