Allosterically coupled multi-site binding of T to human serum albumin

madman · Jul 24, 2022

What's Coming? Accurate measurement of total and free testosterone levels for the diagnosis of androgen disorders - Excel Male Health Forum

Accurate measurement of total and free testosterone levels for the diagnosis of androgen disorders (7/2022) Ezgi Caliskan Guzelce, MD, Clinical/ Research Fellow, Francesca Galbiati, MD, Fellow, Anna L. Goldman, MD, Assistant Professor of Medicine, Arijeet K. Gattu, MD, Fellow, Shehzad Basaria...

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madman · Oct 11, 2025

* the experimental data does not conform to the linear model (Vermeulen) of testosterones binding and we've shown this also for estradiol, so both for estradiol and testosterone the experimental data do not conform to the linear model, in addition what we have found is that the apparent binding affinity varies dynamically with changes in estradiol and SHBG concentrations

Implications of the Inter-monomeric Allostery and Dynamic Changes in Binding Affinity of SHBG and Albumin

Physiologic Implications:

Inter-monomeric allostery in SHBG extends the range of hormone concentrations that SHBG can bind and confers versatility in ligand binding.

Clinical Implications:

- Legacy linear models/equations unlikely to estimate free T or E2 accurately:

- Direct measurements of free T by equilibrium dialysis is ideal, but the binding models that consider the inter-monomeric allostery, the influence of other hormones, can provide better approximation.

The Binding Isotherms of Testosterone Binding to SHBG Exhibit a Multiphase Profile and Do not Conform to a Single Kd

Apparent Kd of Estradiol's Binding to SHBG Changes Dynamically with SHBG and E2 Concentrations and Involves Inter-Monomeric Allostery

Implications of the Inter-monomeric Allostery and Dynamic Changes in Binding Affinity of SHBG and Albumin

28:58-34:36

Thread 'Dr. Shalender Bhasin: Optimizing the Diagnosis and Treatment of Hypogonadism 2025'

Oct 7, 2025

Nelson's house u heard it here first!

Dr. Shalender Bhasin!

* over the past 4 decades he has become a global leader in the biology of androgens, sarcopenia and aging related functional decline, his research has shaped clinical guidelines, its informed public health policy particularly around testosterone therapy, anabolic interventions and then the development of function promoting therapies

Pay attention to 25:40-34:36 of the presentation where he explains the importance of measuring free testosterone using a standardized Equilibrium Dialysis method!

Explains the...

madman · Nov 30, 2025

Thread 'Novel insights into the binding of SHBG with estradiol (EST), dihydrotestosterone (DHT), and testosterone (TES)'

Nov 30, 2025

Complex allosteric mechanism!

* The transport of sex steroid hormones in the plasma is largely mediated by sex-hormone binding globulin (SHBG). SHBG is a functional homodimer, meaning it can bind two sex hormones with similar affinities. This binding occurs through a complex allosteric mechanism. This globulin plays a pivotal role in regulating the availability of sex hormones within target tissues and cells.

* The analysis of representative conformations of the highest and lowest interaction energies revealed a high degree of similarity in...