Production of RNA and Artificial Top Component from Parsley Carrot-leaf Virus Heated In vitro

• Published in: Journal of general virology Vol. 35; no. 1; pp. 25 - 35
• Main Authors: Quacquarelli, A, Piazzolla, P, Avgelis, A, Gallitelli, D
• Format: Journal Article
• Language: English
• Published: Soc General Microbiol 01-04-1977
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-35-1-25

Istituto di Patologia Vegetale, Università degli Studi, Bari, Italy
The extinction-temperature profile of parsley carrot-leaf virus in 0.02 M -(Na-K) phosphate buffer, pH 7.2, containing 0.1 M -NaCl, was determined. At the T d (dissociation temperature = 65 °C), the point at which E 260 begins to increase, the virus particles apparently dissociate to form RNA and empty protein shells (top component). At the T f (temperature at the inflexion point of the curve = 70 °C), corresponding to half the maximum increase in E 260 , the protein denatures and precipitates. Temperatures below T d have little effect on the virus, whereas temperatures higher than T f also degrade the RNA. The results of the present work seem to suggest that the increase in E 260 of PCLV preparations upon heating is mostly attributable to turbidity caused by coat protein denaturation rather than to effects on RNA.
Received 9 August 1976;
accepted 20 October 1976.