Biophysical Studies of the Virus System of Vesicular Stomatitis

Abstract

SUMMARY : Biophysical studies of the virus system of vesicular stomatitis passaged in eggs showed that the major part ofthe infectivity was associated with a component of sedimentation coefficient 625 S. A component of sedimentation coefficient 330 S was observed also, and is probably a non-infective product of the disintegration of the 6 2 5 s component. These components contribute about 35 yo of the total complement-fixing activity of the virus system. All infective materials were handled in subdued light (Skinner & Bradish, 1954). Electron micrographs of concentrates of the infective fraction revealed rods, of length 175 mp. and diameter 69 m p , and almost spherical granules of diameter 65 mp. These particles are identified with the 6 2 5 s and 330s sedimentation components. The remaining 65 Yo of the total complement-fixing activity was associated with two discrete components of sedimentation coefficients about 2 0 s and 6 s . The first of these components may contribute up to 0.1 yo of the total infectivity of the virus system. The structure of the virus system is discussed in relation to the data obtained.Ultracentrifugal studies of the virus system of foot-and-mouth disease (Bradish, Brooksby, Dillon & Norambuena, 1952) demonstrated that infectivity and complement-fixing activity were associated with discrete components of sedimentation coefficients 70 S and 8 S, respectively. These values correspond with equivalent particle diameters of about 20 and 7 mp., respectively. The extension of studies of this type to the virus system of vesicular stomatitis presents advantages because of the greater mass of the infective particle which, on the basis of earlier ultrafiltration and ultracentrifugation data (Galloway & Elford, 1933; Elford & Galloway, 1937) has an equivalent diameter of about 75 mp. This larger particle facilitates the use of certain biophysical methods which were not employed in the previous study (Bradish et al. 1952). Of particular value is the comparison which may be made between the data obtained by the biological assay of ultracentrifugal fractions and those derived by direct optical-analytical ultracentrifugation and by electron microscopy. The results obtained are presented in this paper. METHODS Handling in subdued lightIt was observed by Skinner & Bradish (1954) that the infectivity of suspensions of many viruses, including those of the virus of vesicular stomatitis, was decreased significantly by exposure to light. Special precautions were taken

The Morphology of Vesicular Stomatitis Virus (Indiana C) Derived from Chick Embryos or Cultures of BHK21/13 Cells

“…The 15 mp strand may arise as a filamentous extrusion from the 3rd and 4th structural layers (Fig. 2) and is consistent with the slowly sedimenting (Bradish et al 1956) and rapidly diffusing (Warrington, 1965) infective component.…”

“…and then to rest in the L40 tubes. Sampling operations in subdued light and recoveries of infectivity were generally as described by Bradish, Brooksby & Dillon (1956).…”

Electron Microscopic Studies on the Development of Vesicular Stomatitis Virus in Kb Cells

“…makes it difficult to correlate the observed different forms (rods and spherical particles) with a sequence of developing structures. One can speculate, however, about the development of the virus rods from the spherical particles for the following reasons: (a) the 60-to 65-m# particles (which possibly represent the noninfectious complement-fixing particles described by Bradish et al (2)) and the virus rods were visible inside the same vacuole (Fig. 7) ; and (b) the diameter of 60 to 65 m/z was also found for the core of the 90-to 100-m/z particles (Fig.…”

“…Their dimensions have been reported to be 210 )< 60 (1) or 175 )< 69 mg (2). Furthermore, Bradish et al (2) found non-infectious spherical particles, 65 mg in diameter, possessing a virusspecific complement-fixing activity.…”

“…Their dimensions have been reported to be 210 )< 60 (1) or 175 )< 69 mg (2). Furthermore, Bradish et al (2) found non-infectious spherical particles, 65 mg in diameter, possessing a virusspecific complement-fixing activity. By negative staining with phosphotungstic acid, it was shown (3,4) that each rod had a round and a square end, and there was evidence of an internal component, probably helical (4).…”