BACTERIOPHEOPHYTIN-CONTAINING PARTICLES 117 



400 



600 



800 m/j 



Fig. 2. Upper curve: Absorption spectrum of bacteriopheophytin pre- 

 pared from purified bacteriochlorophyll by acidification with aqueous 

 acetic acid in acetone. Resulting bacteriopheophytin extracted with 

 ethyl ether. Spectrum measured in dry ethyl ether after removal of 

 acetic acid and acetone. 

 Lower curve: Spectrum of B794 extract in dry ethyl ether. 



An additional observation points to the possible identity of the 

 material giving rise to the 800 niju peak in "normal" chromatophores 

 and the 794 m/i peak in the "abnormal" particles: the treatment of 

 both types of preparations with dilute KOH (pH 10) leads to a shift of 

 the 800 mju peak or of the 794 m/i peak to 754 m/i; the position of the 

 latter peak is identical in the two preparations. 



Work is in progress to establish a difference spectrum between 

 "normal" chromatophores and B794 particles in an effort to obtain an 

 approximation of the in situ absorption spectrum of Bsso alone. Also, 

 we hope to be able to separate particles containing only the 880 mju 

 peak and thereby obtain the in situ spectrum of Bgso directly. 



