Some Binding Parameters of Chromatin Acidic Proteins with High Affinity for Deoxyribonucleic Acid

Abstract

A fraction of chromatin acidic protein from rat liver, predominantly comprised of low-molecular-weight species, showed highest in vitro affinity for DNA when compared with other fractions of nuclear acidic protein. Maximum binding of this protein fraction was observed at physiological ionic strength of 0.14 M NaCl and DNA/protein ratio > 1. Comparison of their binding to homologous and heterologous DNAs showed partial species specificity. All molecular species of this protein fraction appear to bind to DNA.