293 



I 



Fulvio Perini 



yielding three fractions: l) 0. 5-0. 7 sat. containing a flavo- 

 proteinj 2) 0.7-0.9 sat. containing cytochrome c-552; 

 3) 0.9-1.0 sat. containing PPNE. 



PHYSICAL AND CHEMICAL PROPERTIES 

 Cytochromes c-552 and 356 



These have been described in a previous report and by Wolken 

 and Gross. They are summarized in Table 1. 



The spectrum of cytochrome c-552 is sho\>m in fig. 1. 



0.5 ■ 



' 04 



5 03 



< 



0.2 



01 



Cytochrome 552 



250 350 450 550 



Wove'eng th ( mi; 1 



250 350 4b0 550 



Wovelength fm^ ) 



Fig. 1. Absorption spectra of Fig. 2. Absorption spectra of 

 reduced (continuous line) and oxi- reduced (continuous line) and ox- 

 dized(broken line) cytochrome c-552. idized(broken line) cytochrome 556. 



Cytochrome c-552 is an acidic c-type cytochrome of 13-1^1,000 mo- 

 lecular veight per haera iron atom, as detemiined by sedimentation- 

 diffusion, amino acid coniposition, iron and haem analysis. 



