ABSTRACT
This chapter provides a modicum of background information on the high-mobility group (HMG) proteins. It describes the HMG proteins to be the calf thymus prototypes (HMG-1, -2, -14, and -17) and proteins closely related in amino acid sequence to one of those four proteins. NaCl or perchloric acid extracts were treated with trichloroacetic acid (TCA) and/or acetone to yield preparations of HMG proteins at various levels of purifications. In 1973, Goodwin et al. reported a simple procedure for obtaining a relatively small set of distinctive, NaCl-dissociated calf thymus NHC proteins. They called the set of proteins the high mobility group, and showed that the calf thymus HMG proteins had the following properties. These properties are they could be extracted from chromatin with 0.35 M NaCl; soluble in 2% TCA; relatively high mobilities in an acid/urea polyacrylamide gel electrophoresis system and they had strikingly high contents of both acidic and basic amino acid residues.
