Interaction of hydrogen peroxide with ribulose-1,5-bisphosphate carboxylase/oxygenase from rice.
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.
Li
Sen
S
Department of Biological Science and Biotechnology, Tsinghua University, Beijing 100084, PR China.
Lu
Wei
W
Li
Guo-Fu
GF
Gong
Yan-Dao
YD
Zhao
Nan-Ming
NM
Zhang
Rong-Xian
RX
Zhou
Hai-Meng
HM
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
D006861:Hydrogen Peroxide; D012273:Ribulose-Bisphosphate Carboxylase