Studies on a protochlorophyll-protein complex I. Purification and molecular-weight determination

摘要: Abstract An active protochlorophyll-protein complex was isolated from dark-grown bean leaves and purified by ammonium sulphate fractionation, treatment with calcium phosphate gel, density-gradient centrifugation electrophoresis. The purification followed spectrophotometric ultracentrifugal analyses it concluded that the protochlorophyll associated a protein boundary sedimentation coefficient of 18 S. However, this at least two components which could be partly resolved zone electrophoresis in density gradient. It appears protochlorophyll-containing contaminated colourless sediments same rate. Evidence also obtained for separation an inactive form protochlorophyll. molecular weight calculated as 600 000 ± 50 measurements (18.0 S), diffusion (2.70 × 10 −7 cm 2 /sec8, partial specific volume (0.73 ml/g). Electron microscopy indicated approximately spherical molecule. In most preparations, there average one molecule per