Purification of the endogenous glucocorticoid receptor stabilizing factor

Journal Article · Tue Sep 03 00:00:00 EDT 1991 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00099a018· OSTI ID:5822901

Meshinchi, S; Stancato, L F; Pratt, W B ^[1]; Gordon, B M; Jones, K W ^[2]

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1. Univ. of Michigan, Ann Arbor (United States)
2. Brookhaven National Lab., Upton, NY (United States)

A ubiquitous, low molecular weight, heat-stable component of cytosol stabilizes the glucocorticoid receptor in its untransformed state in association with hsp90. This heat-stable factor mimics molybdate in its effects on receptor function, and it has the heat stability, charge, and chelation properties of a metal oxyanion. In this paper, the authors describe the further purification of the endogenous factor from rat liver cytosol by anion-exchange HPCL (Ion-110) after prepurification by molecular sieving, cation absorption, and charcoal absorption. Elution of the factor with an isocratic gradient of ammonium bicarbonate results in recovery of all of the bioactivity in a single peak which coelutes with inorganic phosphate and contains all of the endogenous molybdenum. The bioactivity can be separated from inorganic phosphate by chromatography of the partially purified endogenous factor on a metal-chelating column of Chelex-100. The chelating procedure results in complete loss of bioactivity with recovery of 98% of the inorganic phosphate in both the column drop-through and a subsequent 1 M NaCl wash. These observations support the proposal that an endogenous metal can stabilize the binding of hsp90 to the receptor but it is likely that other cytosolic components that are not present in the immunopurified complex must contribute to the stability of the soluble protein-protein complex in cytosol.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5822901
• Journal Information: Biochemistry; (United States), Vol. 30:35; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
GLUCOCORTICOIDS
RECEPTORS
PROTEINS
PURIFICATION
IODINE 125
ION EXCHANGE
ION EXCHANGE CHROMATOGRAPHY
LIVER
RATS
THERMAL SHOCK
TRITIUM COMPOUNDS
ADRENAL HORMONES
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
CHROMATOGRAPHY
CORTICOSTEROIDS
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
ELECTRON CAPTURE RADIOISOTOPES
GLANDS
HORMONES
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IODINE ISOTOPES
ISOTOPES
KETONES
MAMMALS
MEMBRANE PROTEINS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PREGNANES
RADIOISOTOPES
RODENTS
SEPARATION PROCESSES
STEROID HORMONES
STEROIDS
VERTEBRATES
550200* - Biochemistry