TY - JOUR
T1 - Effect of alkaline pH on taxol-microtubule interactions
AU - Ringel, I.
AU - Horwitz, S. B.
PY - 1991
Y1 - 1991
N2 - Taxol stabilizes microtubules against the depolymerizing effects of cold temperature, drugs and Ca++. In this report, the effect of alkaline pH on microtubules polymerized in the presence of taxol has been studied. Although taxol-microtubules are more stable than microtubules assembled in the presence of GTP, taxol-microtubules can be partially disassembled when the pH becomes more alkaline. A portion of the recovered tubulin dimer is assembly competent upon pH adjustment to ~6.6 and the microtubules formed upon the induction of assembly by GTP are normal as judged by electron microscopy. The data indicate that alkaline pH can be used to recover assembly-competent tubulin from a taxol-microtubule complex. At pH 6.6, taxol-induced polymers consisted of two components. The majority were microtubules, but in addition hoops and ribbons were also present. At alkaline pH, the microtubules were more stable than the hoops and ribbons and at pH > 7.5 they were the only stable structures. Microtubules stabilized by taxol are protected against the depolymerizing action of podophyllotoxin even at alkaline pH, whereas the hoops and ribbons are depolymerized.
AB - Taxol stabilizes microtubules against the depolymerizing effects of cold temperature, drugs and Ca++. In this report, the effect of alkaline pH on microtubules polymerized in the presence of taxol has been studied. Although taxol-microtubules are more stable than microtubules assembled in the presence of GTP, taxol-microtubules can be partially disassembled when the pH becomes more alkaline. A portion of the recovered tubulin dimer is assembly competent upon pH adjustment to ~6.6 and the microtubules formed upon the induction of assembly by GTP are normal as judged by electron microscopy. The data indicate that alkaline pH can be used to recover assembly-competent tubulin from a taxol-microtubule complex. At pH 6.6, taxol-induced polymers consisted of two components. The majority were microtubules, but in addition hoops and ribbons were also present. At alkaline pH, the microtubules were more stable than the hoops and ribbons and at pH > 7.5 they were the only stable structures. Microtubules stabilized by taxol are protected against the depolymerizing action of podophyllotoxin even at alkaline pH, whereas the hoops and ribbons are depolymerized.
UR - http://www.scopus.com/inward/record.url?scp=0026347760&partnerID=8YFLogxK
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C2 - 1682488
AN - SCOPUS:0026347760
SN - 0022-3565
VL - 259
SP - 855
EP - 860
JO - Journal of Pharmacology and Experimental Therapeutics
JF - Journal of Pharmacology and Experimental Therapeutics
IS - 2
ER -