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Independent Functions of Viral Protein and Nucleic Acid in Growth of Bacteriophage. September 20, 1952.

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Title:	Independent Functions of Viral Protein and Nucleic Acid in Growth of Bacteriophage [10 of 18]
Creator:	Chase, Martha
Contributor:	Hershey, Alfred Day, 1908
Publisher:	Journal of General Physiology
Date:	1952-09-20
Subject:	Molecular biology Molecular genetics
Description:	From the Journal of General Physiology Vol. 36, No. 1.
Type:	Text
Format:	text/plain
Language:	en
Identifier:	hersheychase-pg10.jpg
Source:	Master scanned with Epson GT-10000+ flatbed scanner at 600 dpi.
Rights:	http://osulibrary.orst.edu/specialcollections/coll/pauling/dna/copyright.html
Full Text:	48 VIRAL PROTEIN AND NUCLEIC ACID I1 BACTERIOPHAGE GROWTH this way may be related to those responsible for the release of bacterial com- ponents from infected bacteria (Prater, 1951; Price, 1952). A variant of the preceding experiments was designed to test bacteria at a later stage in the growth of phage. For this purpose infected cells were aerated in broth for 5 or 15 minutes, fixed by the addition of 0.5 per cent (v/v) com- mercial formalin, centrifuged, resuspended in 0.1 per cent formalin in water, and subsequently handled as described above. The results were very similar to those already presented, except that the release of P3= from the cells was slightly less, and titrations of infected cells could not be made. The S'4-labeled material detached from infected cells in the manner de- scribed possesses the following properties. It is sedimented at 12,000 G, though less completely than intact phage particles. It is completely precipitated by The infected bacteria were suspended at 10° cells per ml. in water containing per liter 1 mm DigSO,, 0.1 mgt CaCI:, and 0.1 gm. gelatin. Samples were withdrawn for assay of extracellular isotope and infected bacteria before and after agitating the suspension. In either case the cells spent about 15 minutes at room temperature in the eluting fluid. antiphage serum in the presence of whole phage carrier. 40 to SO per cent of it readsorbs to sensitive bacteria, almost independently of bacterial concen- tration between 2 X 103 and 109 cells per ml., in 5 minutes at 3i°C. The ad- sorption is not very specific: 10 to 25 per cent adsorbs to phage-resistant bac- teria under the same conditions. The adsorption requires salt, and for this reason the efficient removal of S's from infected bacteria can be accomplished only in a fluid poor in electrolytes. The results of these experiments may be summarized as follows: 1. 75 to 80 per cent of the phage sulfur can be stripped from infected cells by violent agitation of the suspension. At high multiplicity of infection, nearly 50 per cent elutes spontaneously. The properties of the S''-labeled material show that it consists of more or less intact phage membranes, most of which have lost the ability to attach specifically to bacteria. 2. The release of sulfur is accompanied by the release of only 21 to 35 per