ABSTRACT
This chapter deals with the properties of alkaline and neutral proteinases and their function for the intranuclear processing of 60-k protein. The alkaline and neutral proteinase activities were extractable from fractions of nuclei and chromatin at an acidic pH in the presence of a high ionic strength. The extraction of alkaline and neutral proteinases was attempted by suspending fractions of chromatin or nuclei in various solvents. It is generally accepted that in vivo in the nuclei, nonhistone proteins have high turnover rates, while histones are highly conserved. The nuclear fractions were divided into the two fractions, nucleoli and the remaining extranucleoli. The specific activity of alkaline proteinase was significantly higher with nucleoli than with extranucleoli, whereas that of neutral proteinase was appreciably higher with extranucleoli than with nucleoli. In nuclei, alkaline proteinase is bound to nucleoli, which have the gene for the ribosomal RNA.
