DEGRADATION OF ALFALFA MOSAIC VIRUS BY PANCREATIC RIBONUCLEASE

When bottom component and top component a of AMV are treated with ribonuclease in 0.01 M NaH2PO4, pH 7.0, at 4°, RNA is rapidly released from both particles, causing a specific side-by-side aggregation of the RNA-deficient bottom component and a slower aggregation of the RNA-deficient top component a. When this treatment is performed in 0.1 M NaH2PO4, pH 7.0, at 4°, hardly any aggregation occurs. In this buffer both components change into small spherical particles of distinct sizes. Fixation with formaldehyde stabilizes the protein coats to such an extent that they remain intact, even when about all the RNA is released from the bottom component and about 80% of the RNA from top component a. After a short ribonuclease treatment the electrophoretic mobility of top component a toward the positive pole is decreased, indicating that a reduction of the negative surface charge has occurred. The data obtained point to a partial localization of the RNA near the surface of these AMV components. © 1969.