The retention of core ribonucleoproteins in the nuclear matrix isolated from nuclei treated with the...

The nuclear matrix isolated from rat liver nuclei whose protein sulfhydryl groups were oxidised with the o-phenantroline-copper (OP-Cu) complex was enriched with a set of 32-44 kd polypeptides identified as core proteins of ribonucleoprotein particles (RNP). The most conspicuous protein in the nuclear matrix was a 36 kd protein present as a disulfide-linked homodimer. The propensity of protein 36 to be oxidised and form intermolecular associations suggests that it may contribute to the interaction of RNP particles with the nuclear matrix and thus to their spatial distribution in the nucleus.