A receptor protein-based bioassay for quantitative determination of paclitaxel.
A novel receptor-based bioassay for the quantitative measurement of Taxol was developed. The assay was based on the well-investigated and established finding that Taxol, its active analogs, and active metabolites bind reversibly to the receptor protein tubulin, a process similar to antibody and antigen interaction. The assay was performed in a competitive format by allowing a mixture of horseradish peroxidase-labeled Taxol and Taxol in the analyte sample to compete for the Taxol binding site of a polystyrene microtiter plate wall coated with purified tubulin and subsequently measuring the tubulin-Taxol complex by determining the activity of the horseradish peroxidase label. Using this method, Taxol was measured very sensitively, linear range of 0.0001-1 nM, and selectively, without interference from non-tumor-active compounds such as baccatin III, cephalomaninne, and 10-deacetyl taxol. The method was applied for the determination of picomolar concentrations of Taxol in human plasma.
Suye
S
S
Chemical Engineering Department, University of California, Riverside 92521, USA.
Tandel
S
S
Mulchandani
A
A
D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000032:analysis*; D002417:Cattle; D006801:Humans; D017239:Paclitaxel / Q000032:analysis*; D011485:Protein Binding; D011955:Receptors, Drug / Q000737:chemistry* / Q000302:isolation & purification; D014404:Tubulin / Q000737:chemistry / Q000302:isolation & purification
D000972:Antineoplastic Agents, Phytogenic; D011955:Receptors, Drug; D014404:Tubulin; D017239:Paclitaxel