Specific Binding of Human Corticosteroid-Binding Globulin to Cell Membranes

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 83; no. 10; pp. 3253 - 3256
• Main Authors: Hryb, Daniel J., Khan, M. Saeed, Romas, Nicholas A., Rosner, William
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences of the United States of America 01.05.1986; National Acad Sciences
• Subjects: Albumins - metabolism; Animals; Binding sites; Biological and medical sciences; Biological Transport; Cell Membrane - metabolism; Cell membranes; Cell physiology; Female; Fundamental and applied biological sciences. Psychology; Globulins; Hormonal regulation; Humans; Kinetics; Liver; Liver cells; Macaca mulatta; Male; Molecular and cellular biology; P branes; Prostate; Prostate - metabolism; Receptors; Receptors, Cell Surface - metabolism; Sex Hormone-Binding Globulin - metabolism; Steroid hormones; Steroids; Temperature; Tissue Distribution; Transcortin - metabolism; Transferrin - metabolism; Human; Corticosteroid; Binding protein; Membrane receptor; Steroid hormone; Plasma membrane; Mechanism of action; Prostate; Biological receptor
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.83.10.3253

Specific binding sites for corticosteroid-binding globulin were detected on membranes prepared from human prostates. The binding sites are typical of membrane receptors: they are saturable and specific and have high affinity. There was little specific binding at 4 degrees C and 23 degrees C. Maximal specific binding was obtained at 37 degrees C. Scatchard analysis revealed the presence of a single set of binding sites with an apparent dissociation constant of 8.7 × 10-7 M and a binding capacity of 22 pmol/mg of membrane protein. The sites were specific for corticosteroid-binding globulin; binding was not inhibited by human testosterone/estradiol-binding globulin, by albumin, or by transferrin. The density of specific binding sites in membranes obtained from several organs from the rhesus monkey is consistent with the hypothesis that corticosteroid-binding globulin is involved in the transport of steroid hormones into target tissues.