title: Inverse relationship between hSHBG affinity for testosterone and hSHBG concentration revealed by surface plasmon resonance.
abstract: A wide range of human sex hormone-binding globulin (hSHBG) affinity constants for testosterone (KA_hSHBG) has been reported in literature. To bring new insight on the KA_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 KA_hSHBG was obtained from a set of sensorgrams and curve-fitting these data. We observed that KA_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 KA_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.
authors.affiliation: Université de Lyon, Lyon F-69000, France; ISPB Faculté de Pharmacie, MATEIS CNRS UMR5510, Université Claude Bernard Lyon-1, 8 Avenue Rockefeller, cedex 08, Lyon F-69373, France. Electronic address: laurence.heinrich-balard@univ-lyon1.fr.
authors.forename: Laurence
authors.initials: L
authors.lastname: Heinrich-Balard
authors.affiliation: Université de Lyon, Lyon F-69000, France; Groupement Hospitalier Est, Centre de Biologie Est, Laboratoire d'Hormonologie, Hospices Civils de Lyon, Bron 69677, France.
authors.forename: Wael
authors.initials: W
authors.lastname: Zeinyeh
authors.affiliation: Université de Lyon, Lyon F-69000, France; Groupement Hospitalier Est, Centre de Biologie Est, Laboratoire d'Hormonologie, Hospices Civils de Lyon, Bron 69677, France; INSERM U1060 CarMeN, France.
authors.forename: Henri
authors.initials: H
authors.lastname: Déchaud
authors.affiliation: Université de Lyon, Lyon F-69000, France; ISPB Faculté de Pharmacie, MATEIS CNRS UMR5510, Université Claude Bernard Lyon-1, 8 Avenue Rockefeller, cedex 08, Lyon F-69373, France.
authors.forename: Pascaline
authors.initials: P
authors.lastname: Rivory
authors.affiliation: Université de Lyon, Lyon F-69000, France; ISPB Faculté de Pharmacie, MATEIS CNRS UMR5510, Université Claude Bernard Lyon-1, 8 Avenue Rockefeller, cedex 08, Lyon F-69373, France.
authors.forename: Amandine
authors.initials: A
authors.lastname: Roux
authors.affiliation: Université de Lyon, Lyon F-69000, France; INSERM U1060 CarMeN, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Pugeat
authors.affiliation: Université de Lyon, Lyon F-69000, France; ISPB Faculté de Pharmacie, MATEIS CNRS UMR5510, Université Claude Bernard Lyon-1, 8 Avenue Rockefeller, cedex 08, Lyon F-69373, France; Hôpital Edouard Herriot, Laboratoire de Biochimie et de Biologie Moléculaire, Hospices Civils de Lyon, cedex 03, Lyon 69437, France.
authors.forename: Richard
authors.initials: R
authors.lastname: Cohen
mesh_terms: D006801:Humans; D011485:Protein Binding; D012738:Sex Hormone-Binding Globulin / Q000737:chemistry* / Q000378:metabolism; D020349:Surface Plasmon Resonance / Q000379:methods*; D013739:Testosterone / Q000097:blood / Q000737:chemistry*
chemical_list: D012738:Sex Hormone-Binding Globulin; D013739:Testosterone
keywords: SHBG; Surface plasmon resonance; Testosterone; hSHBG affinity