Separation of Rubisco in Extracts of Plant Leaves by Capillary Electrophoresis with Sieving Polymers

Abstract

ABSTRACT Rubisco (Ribulose-1, 5-bisphosphate carboxylase/oxygenase; EC 4.1.1.39) was separated in extracts of plant leaves by capillary electrophoresis with replaceable polymers. Rubisco extracted from plant leaves was fully denatured into small (15.8 kDa) and large (52.9 kDa) subunits in the presence of excess sodium dodecylsulfate (SDS). SDS-Rubisco complexes were separated by using an uncoateda fused silica capillary filled with a replaceable polymer solution, with detection at 220 nm. A calibration plot of Rubisco concentration in plant extract versus peak area was linear over the concentration range of 0.09-1.2 mg mL−1 with a correlation coefficient (r2) of 0.995 and a detection limit of 0.05 mg mL−1. The reproducibility of migration times was less than 0.27% RSD (n=5) and reproducibility of peak area was better than 6.9% The recovery of Rubisco in leaf tissues through the extraction and analysis procedure was 78.2% (±4.8) and through the analysis procedure alone was 96.9% (±5.1). The proposed method was used for the quantification of Rubisco in protein extracts from leaves of a variety of plant species.