Rapid method for the preparation of encephalomyocarditis virus protease from rabbit reticulocyte lysates.

Fractionation of the reticulocyte lysate translation products of encephalomyocarditis virus RNA by ultracentrifugation showed that the viral proteins were distributed differentially in the supernatant and the ribosomal pellet fractions. The viral noncapsid proteins C and D, which contain the viral protease sequence, sedimented preferentially with the pellet fraction. Incubation of the resuspended pellet and subsequent centrifugation of the suspension resulted in cleavage of the protease from proteins C and D and separation of the enzyme from reticulocyte particulate proteins. Preparations thus obtained contained only three encephalomyocarditis virus proteins and were almost devoid of reticulocyte proteins.