Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

delta 9-(16 alpha-/sup 125/I)iodo-19-nortestosterone: a gamma-emitting photoaffinity label for the progesterone receptor

Journal Article · · Endocrinology; (United States)
OSTI ID:7154968
; ; ;

We have synthesized 16 alpha-iodo-4,9-estradien-17 beta-ol-3-one (delta 9-16 alpha-iodo-19-nortestosterone (delta 9-INT)) labeled with 125I (delta 9-(16 alpha-125I)INT) to provide a new gamma-emitting photoaffinity ligand for the progesterone receptor that has many advantages over the currently available (3H)R5020. We have characterized the interaction of delta 9-(16 alpha-125I)INT with the rabbit uterine progesterone receptor and have demonstrated the usefulness of this compound for studies of receptor structure. The binding of 2 nM (3H)progesterone to receptor in rabbit uterine cytosol was specifically competed for by 19-nortestosterone, 16 alpha-iodo-19-nortestosterone, and delta 9-INT. Scatchard analysis demonstrated that delta 9-(16 alpha-125I)INT and (3H)progesterone estimated the same number of binding sites in rabbit uterine cytosol, with a Kd for delta 9-(16 alpha-125I)INT of about 2.7 nM. The binding of delta 9-(16 alpha-125I)INT was inhibited by both progesterone and R5020, whereas testosterone, estradiol, and 5 alpha-dihydrotestosterone were ineffective. In cytosol, delta 9-(16 alpha-125I)INT covalently labeled the same mol wt receptor forms as (3H)R5020. Although the efficiency of cross-linking was similar for (3H)R5020 (3%) and delta 9-(16 alpha-125I)INT (4%), the radioactivity was 10-fold greater due to the higher specific activity of delta 9-(16 alpha-125I)INT and the lack of sample quench. The use of delta 9-(16 alpha-125I)INT greatly increases the sensitivity and efficiency of the photoaffinity labeling technique; it will provide a valuable tool for further studies of the progesterone receptor, allowing the detection of receptor in dilute cytosol after gel electrophoresis under denaturing conditions.

Research Organization:
Baylor College of Medicine, Houston, TX (USA)
OSTI ID:
7154968
Journal Information:
Endocrinology; (United States), Journal Name: Endocrinology; (United States) Vol. 122:5; ISSN ENDOA
Country of Publication:
United States
Language:
English

Similar Records

Regulation of uterine progesterone receptors by the nonsteroidal anti-androgen hydroxyflutamide
Journal Article · Mon Jul 01 00:00:00 EDT 1991 · Biology of Reproduction; (United States) · OSTI ID:5045503
Characterization of R5020 and RU486 binding to progesterone receptor from calf uterus
Journal Article · Tue May 17 00:00:00 EDT 1988 · Biochemistry; (United States) · OSTI ID:7191999
Rat uterine progesterone receptor analyzed by (/sup 3/H)R5020 photoaffinity labeling: evidence that the A and B subunits are not equimolar
Journal Article · Tue Mar 31 23:00:00 EST 1987 · Endocrinology; (United States) · OSTI ID:6526370

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANDROGENS
ANDROSTANES
ANIMALS
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CROSS-LINKING
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHORESIS
FEMALE GENITALS
HORMONES
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KETONES
KINETICS
LABELLED COMPOUNDS
LIGANDS
MAMMALS
MEMBRANE PROTEINS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
POLYMERIZATION
PREGNANES
PROGESTERONE
PROTEINS
RABBITS
RADIOISOTOPES
REACTION KINETICS
RECEPTORS
STEROID HORMONES
STEROIDS
SYNTHESIS
TESTOSTERONE
TRACER TECHNIQUES
TRITIUM COMPOUNDS
UTERUS
VERTEBRATES