A novel bioassay for screening and quantification of taxanes.
We report a novel method for screening and quantifying tubulin-binding antimitotic agents that promote microtubule formation. The method is based on the shift in the peak of the fluorescence emission difference spectrum of tubulin complexed to metal free tetrakis(4-carboxyphenyl)porphyrin (TCPP) in the presence of antimitotic agents. Taxol (paclitaxel), an anti-tumor drug approved for the treatment of a variety of cancers, caused the appearance of a new fluorescence peak at 645 nm at concentrations as low as 125 nM, the intensity of which was a function of the paclitaxel concentration. Cephalomannine caused the induction of a new fluorescence peak at 651 nm only above 1 muM. Baccatin did not induce the appearance of any new peak within detectable operating measurement conditions. These observations are in accordance with the biological activities/cytotoxicities of these compounds. Accordingly, it is proposed that the new method can be used for high throughput screening of antimitotic compounds.
Morais
Sergi
S
Department of Chemical and Environmental Engineering, University of California, Riverside, CA 92521, USA.
Pandey
P C
PC
Chen
Wilfred
W
Mulchandani
Ashok
A
D000972:Antineoplastic Agents, Phytogenic / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D001681:Biological Assay / Q000379:methods*; D005453:Fluorescence; D015394:Molecular Structure; D017239:Paclitaxel / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D011166:Porphyrins / Q000737:chemistry / Q000378:metabolism; D043823:Taxoids / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism*
D000972:Antineoplastic Agents, Phytogenic; D011166:Porphyrins; D043823:Taxoids; D014404:Tubulin; C018395:tetracarboxyphenylporphine; C056348:cephalomannine; D017239:Paclitaxel