Isolation of Nonhistone Proteins from Pig Thymus for Large Scale Preparation

Abstract

A method is described for the large scale isolation of nonhistone proteins from salt-urea dissociated pig thymus chromatin. After precipitating DNA in a dissociated chromatin solution with LaCl₃ at pH 7.9, the chromosomal proteins in the supernatant were precipitated by raising the pH of the supernatant to 8.6. The chromosomal proteins in the precipitate were dissolved and separated into nonhistone proteins and histones by chromatography on SP-Sephadex C-25 using a sodium chloride stepwise elution. Almost all of the total nonhistone proteins in chromatin was eluted from the column at 0.25M and 0.3M NaCl.