The testosterone binding mechanism of an antibody derived from a naïve human scFv library.

A testosterone binding scFv antibody was isolated from a naïve human library with a modest size of 10(8) clones. The crystal structure of the Fab fragment form of the 5F2 antibody clone complexed with testosterone determined at 1.5 Å resolution shows that the hapten is bound deeply in the antibody binding pocket.

Comparison of partial filling MEKC analyses of steroids with use of ESI-MS and UV spectrophotometry.

Until now, partial filling micellar EKC-ESI-MS (PF-MEKC-ESI-MS) has seldom been applied for human biomolecules. In this study, determination of three electrically neutral endogenous steroid hormones, namely androstenedione, testosterone, and epitestosterone, by PF-MEKC-ESI-MS was investigated. Since ESI-MS and ESI-MS/MS behaviors of testosterone and epitestosterone proved to be nearly identical, efficient separation of the two compounds was required to obtain reliable identification.

Determination of association constants between steroid compounds and albumins by partial-filling ACE.

ACE is a popular technique for evaluating association constants between drugs and proteins. However, ACE has not previously been applied to study the association between electrically neutral biomolecules and plasma proteins. We studied the affinity between human and bovine serum albumins (HSA and BSA, respectively) and three neutral endogenous steroid hormones (testosterone, epitestosterone and androstenedione) and two synthetic analogues (methyltestosterone and fluoxymesterone) by applying the partial-filling technique in ACE (PF-ACE).

Microscale immunoaffinity SPE and MEKC in fast determination of testosterone in male urine.

Conventional methods for the determination of testosterone in body fluids typically suffer from poor recovery, lack of specificity, complex sample pretreatment, or the need for derivatization. Here, a simple, specific, and fast analysis method for testosterone was developed, with a methodology based on testosterone-specific immunoaffinity SPE (IA-SPE) and subsequent analysis by partial filling MEKC (PF-MEKC). An immunosorbent consisting of a recombinant antitestosterone Fab fragment covalently attached to activated Sepharose was prepared.

Immunoaffinity CE in clinical analysis of body fluids and tissues.

This paper reviews immunoaffinity CE procedures developed since 1998 for drug, hormone, and disease marker analyses of body fluids and tissues. Immunoaffinity CE and related techniques are described. Examples of clinical applications are included.

Partial filling micellar electrokinetic chromatography analysis of androgens and testosterone derivatives using two sequential pseudostationary phases.

Separation of anabolic and androgenic steroids by micellar electrokinetic chromatography (MEKC) has been little studied. Simultaneous separation of the endogenous alpha-epimers testosterone and epitestosterone has not been achieved with any electroseparation technique. Here, a partial filling micellar electrokinetic chromatographic (PF-MEKC) method is described for the analysis of three endogenous steroid hormones (androstenedione, testosterone, epitestosterone) and two synthetic anabolic steroids (fluoxymesterone, methyltestosterone).

Analysis of anabolic steroids by partial filling micellar electrokinetic capillary chromatography and electrospray mass spectrometry.

A partial filling micellar electrokinetic capillary chromatography (PF-MEKC) separation of six anabolic androgenic steroids (androstenedione, metandienone, fluoxymesterone, methyltestosterone, 17-epimetandienone and testosterone) is introduced. The method utilises a mixed micellar solution consisting of sodium dodecyl sulphate (SDS) and sodium taurocholate. The analytes are detected with a photodiode array detector at 247 nm wavelength.