Studies on the structure of the follicle-stimulating hormone receptor using photoaffinity labeling procedures

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 1985

OSTI ID:5009024

Smith, R A

The general objective of this project was to study the structure of the follicle stimulating hormone (FSH) receptor using affinity labeling methods. A low density fraction derived from homogenates of bovine testis was found to contain high affinity and low capacity receptors specific for FSH. Electron microscopic examination of the fraction revealed structure resembling multilamellar membranous vesicles (MV). For photoaffinity labeling of the FSH receptors in MV, an azidobenzoyl-/sup 125/I-analog of human FSH was prepared (/sup 125/I-AB-hFSH) and binding of specific FSH receptors was studied. /sup 125/I-AB-hFSH binding of receptors was inhibited in a dose dependent manner by unlabeled hFSH, and binding was not prevented by structurally-related human chorionic gonadotropin (hCG). The formation of photocrosslinked protein of relative molecular mass (M/sub r/) 54,000, 64,000, 76,000, 84,000, 97,000 and 116,000 was found to be inhibited by unlabeled hFSH in a dose related manner, and to be dependent on photoactivation of the FSH derivative. The interpretation of the photoaffinity labeling experiments was that three proteins associated with the FSH receptor were photoaffinity labeled. Analysis by indirect means suggested that the three proteins were assembled to form oligomeric complexes, and based on the intensities and composition of the oligomeric species, spatial relationships of the polypeptides with respect to each other on the membrane surface were deduced. The results of photoaffinity labeling suggest the FSH receptor is composed of three subunits of M/sub r/ 38,000, 48,000, and 81,000 and exists in the membrane in part as a M/sub r/ 330,000 dimer.

• Research Organization: Albany Medical Coll., NY (USA)
• OSTI ID: 5009024
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
AZIDO COMPOUNDS
CONFIGURATION INTERACTION
RECEPTORS
AUTORADIOGRAPHY
MOLECULAR STRUCTURE
CATTLE
CELL MEMBRANES
ELECTRON MICROSCOPY
FSH
IODINE 125
MOLECULAR WEIGHT
TESTES
ANIMALS
BETA DECAY RADIOISOTOPES
BODY
CELL CONSTITUENTS
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
ELECTRON CAPTURE RADIOISOTOPES
GONADOTROPINS
GONADS
HORMONES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
MALE GENITALS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
MICROSCOPY
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PEPTIDE HORMONES
PITUITARY HORMONES
PROTEINS
RADIOISOTOPES
RUMINANTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques