[The isolation and characteristics of a protein from human and bovine kidneys close in molecular and biochemical properties to non-histone chromosomal antigen PP23].

By ion-exchange gradient chromatography, autophosphorylated protein fractions were separated from nonhistone chromosomal protein (NHCP) samples isolated from bovine and human kidney and liver. Fractions, eluted from the phosphocellulose column with 0.4-0.5 M NaCl, could occur only in the case of kidney rather than liver NHCP-fractionation. The molecular weight of the major phosphorylated protein component, eluted in this zone, is about 20-26 kDa, which is close to the molecular weight of protein pp23, previously observed during similar fractionation of NHCP from rat kidney rather than from liver.