Absence of 7-acetyl taxol binding to unassembled brain tubulin.
The effect of taxol on microtubule proteins at 0 degrees C is controversial. In order to determine if taxol is unable to bind to unassembled tubulin, as has been hypothesized, the binding of [3H]acetyl taxol has been studied using equilibrium microdialysis. Ac-taxol bound to microtubules at 37 degrees C and the binding remained stable when the temperature was lowered to 0 degrees C. Ac-taxol bound also at 0 degrees C to microtubules stabilized with rhazinilam. In contrast, there was no binding of Ac-taxol to unassembled tubulin, either free tubulin at 0 degrees C or tubulin, complexed with several microtubule poisons, at 0 and 37 degrees C.
Takoudju
M
M
Laboratoire de Pharmacologie et de Toxicologie Fondamentales, Centre National de la Recherche Scientifique, Toulouse, France.
Wright
M
M
Chenu
J
J
Guéritte-Voegelein
F
F
Guénard
D
D
D000470:Alkaloids / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism; D003956:Dialysis; D007700:Kinetics; D008870:Microtubules / Q000378:metabolism; D017239:Paclitaxel / Q000031:analogs & derivatives*; D011485:Protein Binding; D012756:Sheep; D043823:Taxoids; D014316:Tritium; D014404:Tubulin / Q000378:metabolism*
D000470:Alkaloids; D043823:Taxoids; D014404:Tubulin; D014316:Tritium; C043189:7-acetyltaxol; D017239:Paclitaxel