Cypex CYP3A5 QC Assays
buffer: 0.05 M potassium phosphate pH 7.4, 5 mM MgCl2
volume: 200 µl
Stop reagent: 1 M hydrochloric acid (20 µl)
Internal standard: 4-androstene-3,17-dione (10 µl of 10 µg/ml)
Column: Hypersil ODS (5 µm) 250 x 4 mm
Mobile phase: 0.05% orthophosphoric acid/methanol 44/56
(v/v) (isocratic separation)
Flow rate: 1.0 ml/min
Run time: 18.5 min
Injection volume: 50 µl
Detection: UV, l
= 240 nm
of phosphate concentration on testosterone turnover by CYP3A5LR Bactosomes
turnover by CYP3A5 is sensitive to the concentration of phosphate in the incubation.
assay was carried out at 320 µM testosterone at a P450 concentration of
2.5 pmol per 200 µl.
The length of time for which product formation
is linear is also affected by phosphate concentration.
under licence from BTG International Ltd (AU730155, EP0914446, US6566108 and other
United States Patent Nos. 5,420,027 or 5,240,831, Canada
Patent No. 2100245 and other patents pending.