title: Interaction of hydrogen peroxide with ribulose-1,5-bisphosphate carboxylase/oxygenase from rice.
abstract: The properties of rice-derived ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) in different concentrations of hydrogen peroxide (H2O2) solutions have been studied. The results indicate that at low H2O2 concentrations (0.2-10 mM), the properties of rubisco (e.g., carboxylase activities, structure, and susceptibility to heat denaturation) change slightly. However, at higher H2O2 concentrations (10-200 mM), rubisco undergoes an unfolding process, including the loss of secondary and tertiary structure, forming extended hydrophobic interface, and leading to cross-links between large subunits. High concentrations of H2O2 can also result in an increase in susceptibility of rubisco to heat denaturation. Further pre-treatments with or without reductive reagents to rubisco show that the disulfide bonds in rubisco help to protect the enzyme from damage by H2O2 as well as other reactive oxygen species.
authors.affiliation: Department of Biological Science and Biotechnology, Tsinghua University, Beijing 100084, PR China.
authors.forename: Sen
authors.initials: S
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
authors.forename: Guo-Fu
authors.initials: GF
authors.lastname: Li
authors.forename: Yan-Dao
authors.initials: YD
authors.lastname: Gong
authors.forename: Nan-Ming
authors.initials: NM
authors.lastname: Zhao
authors.forename: Rong-Xian
authors.initials: RX
authors.lastname: Zhang
authors.forename: Hai-Meng
authors.initials: HM
authors.lastname: Zhou
mesh_terms: D002942:Circular Dichroism; D004591:Electrophoresis, Polyacrylamide Gel; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000378:metabolism*; D012275:Oryza / Q000201:enzymology* / Q000378:metabolism; D011489:Protein Denaturation; D012273:Ribulose-Bisphosphate Carboxylase / Q000737:chemistry / Q000378:metabolism*; D013050:Spectrometry, Fluorescence
chemical_list: D006861:Hydrogen Peroxide; D012273:Ribulose-Bisphosphate Carboxylase