Nondenaturing electrophoresis. Fractionating of photosynthetic pigment--protein complexes and blood plasma proteins.

Efficient polyacrylamide gel electrophoresis of labile proteins and protein complexes is reviewed. If only 0.001-0.01% SDS is dissolved in the electrode buffers, the detergent does not exhibit denaturing activity and guarantees high quality of electrophoresis. Even the structure and oxygen-producing activity of the labile photosystem PS2 are preserved after electrophoretic separation of photosynthetic pigment--protein complexes from Anacystis nidulans R2 or other cyanobacteria. The overall spectra of absorption or fluorescence of isolated pigment--protein complexes are equal to the corresponding spectra of the photosynthetic membrane. The distribution of chlorophyll molecules between the components of the photosynthetic apparatus coincides in spectral analysis data and gel fraction densitometry. More than 15 electrophoretic fractions of pigment--protein complexes of chloroplasts from green algae and higher plants were observed including some fractions of PS1, some spectrally different forms of light harvesting pigment--protein complexes, and their oligomers. High resolving capacity of electrophoresis was demonstrated by separation of plasma proteins. Low denaturing activity and low thermal dissipation of the electrode buffer solution allow the use of large diameter tubes (3.5 and 8 cm) in polyacrylamide gel electrophoresis. The cell destruction time and the membrane dissolving time are minimized. The method of electrophoretic staining of the gels was tested.