Letter: Action of heparin on nuclei: solubilization of chromatin enabling the isolation of nuclear membranes.

Abstract

INTERACTIONS of natural and synthetic polyanions with chromatin are well documented, both at the structural and functional level. Frenster1 has shown that polyanions can enhance RNA transcription of chromatin, and this has been further studied by Chambon et al.2,3. Kraemer and Coffey4 have established that morphological modifications such as swelling of nuclei, loosening of the chromatin, and nuclear DNA release correlate with polyanion action5. All these phenomena have been logically interpreted as interactions of polyanions with histones leading to the release of genetic restrictions that histones produce, and Miller et al.6 and Berlowitz et al.7 have shown that selective binding of histones occurs. Arnold et al.8 have made an extensive morphological study of the structural alterations that are produced in nuclei by those polyanions which are capable of removing template restrictions. In all cases, molecular weights of the polyanions seem to be important4–8. As natural nuclear polyanions are known to occur, several theories have been proposed concerning the biological relevance of the above data1–9.