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Isolation and Characterization 

 of Bacterial Nucleoprotein Particles 



WILLIAM C. GILLCHRIEST ROBERT M. BOCK 



Department of Biochemistry, University of Wisconsin 



Fractionation of the particulate matter from broken cells has long excited 

 the biochemist. Lilienfeld [1] prepared nuclear and cytoplasmic fractions and 

 studied the properties of a deoxynucleoprotein (DNP). Huiskamp [2] noted 

 the influence of buffer salts on isolated DNP. The possibility of differential 

 extraction of subcellular structures was investigated by Bensley and Hoerr [3]. 

 The technique of purifying subcellular components has advanced rapidly 

 through the efforts of Claude [4], Hogeboom and Schneider [5], and 

 Anderson [6]. 



The fractionation of subcellular components offers the possibility of integrat- 

 ing the fields of intracellular anatomy, cellular physiology, and biochemistry. 

 Siekevitz [7] working with mitochondria and Palade [8] and Zamecnik [9] 

 working with the microsomal fraction have begun this integration by equating 

 isolated fractions to structures observed in the electron microscope. Our studies 

 with the ribonucleoprotein of Azotobacter vinelandii have clearly demon- 

 strated that progress in this integration of fields demands a detailed under- 

 standing of the properties and stability of the subcellular particles. Previous 

 studies [10] on the protein synthesis in cell-free extracts of A. vinelandii must 

 now be reinterpreted in the light of our current understanding of the stability 

 of bacterial ribonucleoprotein. 



In 1954 Palade and Porter [8a] demonstrated endoplasmic reticulum in ani- 

 mal cells. Hodge, Martin, and Morton [11] in 1957 demonstrated similar struc- 

 tures in plant cells, and Sacks [12] has found related structures in yeasts, higher 

 molds, and algae, leaving, at the present time, only the bacteria without clearly 

 demonstrated endoplasmic reticulum. Pochon [13] found structures in A. vine- 

 landii which by staining and observation in the light microscope were identi- 

 fied as nuclei. We have observed granularity in regions of thin sections through 



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