Physical and Chemical Properties of Cynosurus Mottle Virus

Abstract

SUMMARYParticles of cynosurus mottle virus (CyMV) purified from systemically infected oat leaves have a sedimentation coefficient of I I3S, buoyant density of 1.399 g [ml in CsC1 and I'332 in Cs~SO4, diffusion coefficient of o'I3OX IO-l°m2/s and E0.1% of 7"3. Virus particles are isometric with a diameter of 27 to 29 nm in 260 negatively stained preparations; the hydrodynamic diameter was calculated from the D20. w as 32"8 nm. The particle mol. wt. was calculated as 6.86 x io G. CyMV particles contain 22. 5 °/o single-stranded'RNA of mol. wt. approx. 1"5 × IO ~ and a molar nucleotide composition of: A, 24"2%; G, 24"3%; C, 26"2~o and U, 25.3%; RNA purified by the phenol-SDS method was infectious. The melting profile of native CyMV-RNA was typical of a single stranded RNA with secondary structure; the hyperchromicity was 33 % and the Tm 6I °C. The protein mol. wt. CyMV particles were degraded by o.02 to o'o5 ~o SDS at pH 7.0 into a component with a sedimentation coefficient of 83S and by o.1% SDS into the RNA and protein constituents; virus dissociation was enhanced by EDTA and reduced by MgC12. At pH 5"o, the virus was not affected by SDS concentrations of up to 8 %. The virus was unstable in EDTA and NaC1 at pH 8"25.

Purification and properties of Australian lucerne latent virus, a seed‐borne virus having affinities with nepoviruses

“…Virus protein was prepared by boiling virus preparations for 2 min in 0.005 M sodium phosphate buffer (pH 7.2) containing 5 M urea, 1% sodium dodecyl sulphate (SDS) and 0.5% 2-ME. Electrophoresis in 7.5% polyacrylamide gels was as described by Mohamed (1978) using bovine serum albumin (68000), ovalbumin (43 000), lactic dehydrogenase (36 000), papain (23 000) and cytochrome c (1 1 000) as protein markers.…”

“…wt determined by electrophoresis in 2.2% acrylamide/0.5% agarose composite gels as described by Mohamed (1978). The sedimentation coefficients of viral nucleic acid were determined by centrifuging through linear-log sucrose density gradients at 24 000 rev./min for 16 h in a Beckman SW25 rotor (Brakke & Van Pelt, 1970;Mohamed, 1978). The following marker RNAs were used throughout: E. coli ribosomal R N A (23 S and 16 S, mol.…”

Isolation and Characterization of Subviral Structures from Tomato Spotted Wilt Virus

“…Purified virus particles were dissociated into polypeptides by adding an equal volume of 0.1 M-sodium phosphate buffer, pH 7.2, containing 10 M-urea, 2 % SDS and 0-1% mercaptoethanol and heating at 100 °C for 3 rain. Protein samples were analysed by electrophoresis on 7.5 % polyacrylamide gels (Mohamed, 1978).…”

“…Nucleic acid was prepared from the RNP components either by the single-phase phenol-SDS method (Diener & Schneider, 1968) 1% SDS, 0-5 % mercaptoethanol, 0.05 M-sodium phosphate, 1 mM-EDTA, 10% sucrose, pH 7.4 (Brakke & Rochow, 1974) at 60 °C for 5 min. Nucleic acids were fractionated on 2% acrylamide-0.5% agarose slab gels using the tris-phosphate-SDS buffer system (Loening, 1968); electrophoresis and staining were carried out as described by Mohamed (1978).…”

Cynosurus mottle virus, a virus affecting grasses in New Zealand

“…Antiserum to CyMV was prepared by injecting a rabbit with purified preparations (Mohamed, 1978) of virus; 2 intravenous injections 2 weeks apart were followed by 5 intramuscular injections at lO-day intervals. For intravenous injections, virus in saline solution was used and for intramuscular injections, virus was emulsified with Freund's incomplete adjuvant.…”