306 



T. HoRio, I. Sekuzu, T. Higashi and K. Okunuki 



Table 2, The oxidase contains no copper. The frictional ratio (//^) is calcu- 

 lated to be 1-2. Even after purification to a homogeneous state, P-cytochrome 

 oxidase preparation shows a rather complex absorption spectrum, as if it 

 contained so-called cytochrome a^ and c-type cytochrome. The Oa-type haem 

 is easily extracted in acetone containing HCl according to the method of 

 Barrett (1956) but the c-type haem remains in the acetone precipitate in a 

 state bound to the protein moiety. Approximately half of the iron of the 

 oxidase preparation is found in the acidic acetone extract. Therefore, it is 

 sure that each molecule of P-cytochrome oxidase contains two different kinds 

 of haems, a^-Xy^^Q and c-type. 



Properties of the Respiratory Components Related to the Cytochrome Oxidases 

 Cytochrome c^ can be purified separately from other cytochromes with the 

 aid of cholate from ox-heart muscle. The purified cytochrome c^ does not 

 show enzymic activities such as DPNH-cytochrome c reductase. However, 

 the cytochrome c^ in its reduced form can rapidly transfer an electron to 

 cytochrome c. The general properties of P-cytochrome-551 and P-blue 



0.6 



E 



0.5 



0.4 



0.3 



0.2 



0.1 



Reduced form 



292 



oxidized form 

 630 



2 50 300 350 400 450 500 550 

 WQvelengfh {m>j) 



600 650 700 750 



Fig. 2. Absorption spectra of crystalline Pseudomonas blue protein. The reduced 



form was made by adding sodium borohydride. Compared with the reduction 



of typical cytochrome c's, a much larger amount of the reductant was required 



for complete reduction. 



