| Method |
Samples of protein or ribosomes were hydrolysed with glass redistilled constant-boiling HCI (0'5 ml. for every 3 mg protein) under nitrogen in sealed Pyrex glass tubes in an oven maintained at 110±1°C for 24 and 72 hr, and, in some cases, for 96 hr. The protein was prepared from the ribosomes in two different ways. In the first, the acetic acid procedure, the protein was extracted by 66% acetic acid in the cold, according to Fraenkel-Conrat (1957) and as described by Waller & Harris (1961) The second method, referred to hereafter as the RNase procedure, made use of the fact that there is a latent RNase in the ribosomes (Elson, 1958). |