424 



PHOTOMECHANICAL CONSIDERATIONS 



•ASHED BACTERIA 



in 0.2M \a,CO, 



CRUDE EXTRACT 



centrifuge 140, 000 x G 



(precipitate) 

 CHLOROBIUM CHLOROPHYLL 

 CELL DEBRIS 





add (NH,)^ SO4 

 20% (w,, v) 



dissolve in .OZM 



phosphate buffer, pH 7. 



and dialize 



(adsorbate) 

 CHLOROBIUM CHLOROPHYLL 

 CYTOCHROME 

 NUCLEIC ACIDS 



CYTOCHROME 



(eluate) 

 PROTEIN- CHLOROPHYLL- 770 



Fig. 1. Flow sheet for preparation and purification of the protein- 

 chlorophyll -770 complex from green bacteria. 



tographed (6) on powdered sugar (Jack Frost lOX) using a mixture of 

 2 per cent tetrahydrofuran and 0.75 per cent «-propanol in petroleum 

 ether (Skellysolve B). After development of the sugar column, the blue 

 band at the bottom was dug out and eluted with ether. 



ABSORPTION AND FLUORESCENCE SPECTRA 



The absorption spectrum of the protein- chlorophyll complex is 

 given by the solid curve in Fig, 2, Most of the spectrum is due to the 

 chlorophyll, but the slight shoulder at about 280 mfi is probably due to 

 protein. The absorption spectrum of a typical preparation from C. 

 thiosulfatophilum differs from the solid curve in Fig. 2 mainly in 



