CHL-770 FROM GREEN BACTERIA 



425 



0.9 

 0.8 

 0.7 



0.6 



E 



^ 0.5 



>- 



(_> 



I 0.4 



CO 0.3 



0.2 



0.1 

 



300 



400 



500 



600 700 



X ( m^) 



800 



900 



Fig. 2. Absorption spectrum of the protein-chlorophyll-770 complex from 

 Cps. ethylicum in 0.25 M NaCl and 0.02 M phosphate buffer pH 7.8 after elu- 



tion from diethylaminoethyl cellulose ( ) and absorption spectrum of 



chlorophyll-770 in ether after sugar chromatography ( ). The chloro- 

 phyll concentrations for the two curves are not equivalent. 



having a very high peak at 275 m/i and a very pronounced shoulder at 

 405 m^, which are presumed to indicate contamination by cytochrome 

 and other proteins. 



The absorption spectrum of chlorophyll-770 in ether is given by the 

 dashed curve in Fig. 2. This spectrum, which is virtually the same as 

 that obtained for bacteriochlorophyll from Chromatiiun after sugar 

 chromatography, agrees with the observations based on other species 

 of green bacteria (7,8). The spectral characteristics are presented in 

 Table 1. 



Fluorescence emission spectra for the complex are shown in Fig. 

 3. At 293 °K the main emission band appears at 818 mfi with a broad 

 shoulder on the red side of the main peak. At 77 °K the main peak 

 sharpens and shifts to 827 m/y, and the shoulder is resolved into two 

 minor bands at 880 m/i and 917 m^. The fluorescence yields for 366 

 mfi excitation are 0.19 and 0.29 at 293 °K and 77°K respectively (4). 



