Endocrinology, Vol 107, 994-999, Copyright © 1980 by Endocrine Society
3,5,3'-triiodothyronine receptor-containing chromatin fragments: production by nuclease digestion
DJ Gruol
Nuclear thyroid hormone (T3) receptors are nonhistone proteins which are
tightly bound to rat liver chromatin. The solubilization of the T3
receptors by micrococcal nuclease was studied using an assay which allows
the delection of in vitro hormone binding and which is independent of the
state of solubility of the chromatin. Nuclease digestion produces a
receptor containing moiety which sediments at a rate of 5--6S. This form of
the receptor is different than that released from chromatin at high ionic
strength (3.8S) and potentially represents the stable association of the
receptor which other elements of chromatin. Partial release of chromatin
compaction by the use of dilute buffer solutions increases the rate of
nuclease digestion, facilitates the release of the (5--6S) T3-receptor
complex, and allows the isolation of sucrose gradient fractions which are
enriched with receptor.
