INACTIVATION OF LETTUCE NECROTIC YELLOWS VIRUS BY CHELATING AGENTS

Salicyaldoxime (SALDOX) and sodium diethyldithiocarbamate (DIECA), specific chelators of copper and iron, completely inactivated lettuce necrotic yellows virus (LNYV) at 20° within 1 and 4 hours, respectively. However, two less specific chelating agents, ammonium thiocyanate and disodium ethylenediaminetetraacetic acid, had no effect. The virus was inactivated faster at 30° than at lower temperatures. SALDOX and DIECA degraded the virus to structures which resemble those formed from membranes after exposure to lipase. It is suggested that virus inactivation is caused by the removal of Cu2+ and/or Fe2+ from the virus preparations, thus allowing any lipases present to degrade the viral membrane. This explanation is preferred to those involving either essential metals in the virus structure, or a direct chemical effect of the chelating agents on the membrane. © 1969.