Inactivation of the pseudorabies virus by dithiothreitol

Abstract

The virucidal nature of reduced dithiothreitol (DTT) for the pseudorabies (PR) virus (PRV) is presented. The rate of decay of PRV in DTT increased exponentially as the pH rose from 6.5 to 8. Effective virucidal concentrations of DTT decreased in concentration as the pH was elevated. The reaction rate was temperature dependent under mild alkaline conditions, being essentially nil at 0° and at 20°, but progressively more rapid from 30° to 41°. Electron micrographs indicated substantial disruption of the architecture of the DTT inactivated virions. Preincubation of DTT with catalytic amounts of Cu 2+ or with high concentrations of Mg 2+ decreased the virucidal activity; preincubation with catalytic levels of Fe 3+ lowered activity slightly. Thirteen additional compounds, mostly thiols, were tested for virucidal activities. Reduced dithioerythritol (DTE), an asymmetric isomer of DTT, was considerably less active than DTT. British anti-lewisite (BAL), (2,3-dimercapto-1-propanol), was of the same order of activity as DTE, but 1,3-dimercapto-2-propanol, an isomer of BAL, was essentially nonvirucidal. Thimerosal and iodoacetamide at 0.01 M were virucidal, but 2-mercaptoethanol at 0.01 M was inactive. Trithiodiglycol at 0.01 M, pH 8.0, was moderately virucidal. Oxidized dithiothreitol was nonvirucidal.