Abstract
Plant rubisco consists of eight large subunits 55 kD encoded by chloroplast gene and eight small subunits 15 kD encoded by nuclear gene. Thereare abundant cysteine residues that do not form disulfide bonds in native rubisco. Differential scanning calorimetry has been used to study some plant rubisco and suggested an irreversible two-state denaturation due to the high cooperativity in subunits. By comparing the data from circular dichroism fluorescence differential scanning calorimetry SDS electrophoresis and activity assays in the absence or presence of DTT we suggest that the formation of disulfide bonds in subunits during the early thermal unfolding may increase the thermal stability and the thermal unfolding cooperativity of rubisco.
Supported by the Major State Basic Research and Development Program of China (G1998010100) and the National Natural Science Foundation of China (Grant No. 39890390)
Supported by the Major State Basic Research and Development Program of China (G1998010100) and the National Natural Science Foundation of China (Grant No. 39890390)
Notes
Supported by the Major State Basic Research and Development Program of China (G1998010100) and the National Natural Science Foundation of China (Grant No. 39890390)