Dimethylarsinic acid causes inhibition of microtubule assembly and inhibition of calcium‐sensitive disassembly of microtubules via interaction with glutathione

Abstract
The effects of dimethylarsinic acid (DMAA) on microtubule assembly in vitro were investigated in terms of the role of glutathione (GSH). Increase in turbidity due to assembly of brain tubulins was monitored in the presence or absence of DMAA. DMAA at concentrations up to 10 mM did not cause inhibition of the increased turbidity. GSH at concentrations over 10 mM enhanced the increase in turbidity. By contrast, the increased turbidity was inhibited markedly when DMAA and GSH were combined in the ratio of 5:1. Moreover, the combination similarly inhibited calcium‐induced disassembly of microtubules with a potency equivalent to that of 10 µM taxol. These results suggest that DMAA inhibited not only microtubule assembly, but also calcium‐sensitive disassembly of microtubules, via interaction with GSH. Copyright © 2002 John Wiley & Sons, Ltd.