Inverse relationship between hSHBG affinity for testosterone and hSHBG concentration revealed by surface plasmon resonance. (5th January 2015)

• Record Type: Journal Article
• Authors: Heinrich-Balard, Laurence; Zeinyeh, Wael; Déchaud, Henri; Rivory, Pascaline; Roux, Amandine; Pugeat, Michel; Cohen, Richard
• Is Part Of: Molecular and cellular endocrinology. Volume 399(2015)
• Page Start: 201
• Page End: 207
• Publication Date: 2015-01-05
• Subjects: SHBG -- Surface plasmon resonance -- hSHBG affinity -- Testosterone; Endocrinology -- Periodicals; Molecular biology -- Periodicals; Cytology -- Periodicals; Endocrinology -- Periodicals; Hormones -- Periodicals; Endocrinologie -- Périodiques; Cytology; Endocrinology; Molecular biology; Periodicals; 573.4
• DOI: 10.1016/j.mce.2014.10.002
• Languages: English
• ISSNs: 0303-7207

Abstract

Highlights: We studied the affinity of hSHBG for testosterone by surface plasmon resonance. The affinity constant decreased significantly when hSHBG concentration increased. This result may question the validity of methods for calculating free testosterone. Abstract: A wide range of human sex hormone-binding globulin (hSHBG) affinity constants for testosterone ( K A_hSHBG ) has been reported in literature. To bring new insight on the K A_hSHBG value, we implemented a study of the molecular interactions occurring between testosterone and its plasma transport proteins by using surface plasmon resonance. The immobilization on the sensorchip of a testosterone derivative was performed by an oligoethylene glycol linker. For different plasmas with hSHBG concentrations, an assessment of the K A_hSHBG was obtained from a set of sensorgrams and curve-fitting these data. We observed that K A_hSHBG decreased, from at least two decades, when the plasma hSHBG concentration increased from 4.4 to 680 nmol/L. Our study shows a wide biological variability of K A_hSHBG that is related to the hSHBG concentration. These unexpected results may have a physiological significance and question the validity of current methods that are recommended for calculating free testosterone concentrations to evaluate androgen disorders in humans.