TY - JOUR
T1 - The effects of the anilinonaphthalenesulfonates on the alkylation of tubulin
T2 - correlation between the appearance of sulfhydryl groups and apolar binding sites
AU - Luduena, Richard F.
AU - Roach, Mary Carmen
AU - Horowitz, Paul
N1 - Funding Information:
We gratefully acknowledge the skillful technical assistance of Phyllis Smith and the help of Charlotte Farrell in typing the manuscript. This work was supported by Grants AQ-726 to R.F.L. and AQ-723 to P.H. from the Robert Welch Foundation and Grants CA26376 and GM23476 to R.F.L. and GM25177 to P.H. from the National Institutes of Health.
PY - 1986/9/5
Y1 - 1986/9/5
N2 - We have previously found that the sulfhydryl groups of tubulin are sensitive reporters of the effects of ligands on the tubulin molecule. In this study, we examined the effects of three anilinonaphthalenesulfonates on the interaction of tubulin with iodo[14C]acetamide and N,N′-ethylenebis(iodoacetamied). We found that 1,8-anilinonaphthalensulfonate (1,8-ANS) and 2,6-anilinonaphthalenesulfonate (2,6-ANS) had no effect on the ractiion with iodo[14C]acetamide. In contrast, bis(1,8-anilinonaphthalenesulfonate) (BisANS), an inhibitor of microtubule assembly, had a complex effect. Low concentrations of BisANS, where presumably only the high-affinity binding site was saturated, had little or no effect on alkylation. Higher concentrations of BisANS cause a strong enhancement of alkylation. None of these compounds had any effect on the reaction with N,N′-ethylenebis(iodoacetamide). Our results suggest that the binding of BisANs, 2,6-ANS and 1,8-ANS to tubulin is complex and very different from that of the other anti-tubulin drugs. The correlatiion between the effects of drugs on alkylation of tubulin and the binding of BisANS is consistent with a model whereby the alkylatable sulfhydryls are located in apolar regions of the tubulin molecule.
AB - We have previously found that the sulfhydryl groups of tubulin are sensitive reporters of the effects of ligands on the tubulin molecule. In this study, we examined the effects of three anilinonaphthalenesulfonates on the interaction of tubulin with iodo[14C]acetamide and N,N′-ethylenebis(iodoacetamied). We found that 1,8-anilinonaphthalensulfonate (1,8-ANS) and 2,6-anilinonaphthalenesulfonate (2,6-ANS) had no effect on the ractiion with iodo[14C]acetamide. In contrast, bis(1,8-anilinonaphthalenesulfonate) (BisANS), an inhibitor of microtubule assembly, had a complex effect. Low concentrations of BisANS, where presumably only the high-affinity binding site was saturated, had little or no effect on alkylation. Higher concentrations of BisANS cause a strong enhancement of alkylation. None of these compounds had any effect on the reaction with N,N′-ethylenebis(iodoacetamide). Our results suggest that the binding of BisANs, 2,6-ANS and 1,8-ANS to tubulin is complex and very different from that of the other anti-tubulin drugs. The correlatiion between the effects of drugs on alkylation of tubulin and the binding of BisANS is consistent with a model whereby the alkylatable sulfhydryls are located in apolar regions of the tubulin molecule.
KW - Anilinonaphthalenesulfonate
KW - Apolar binding site
KW - Sulfhydryl group
KW - Tubulin alkylation
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U2 - 10.1016/0167-4838(86)90200-1
DO - 10.1016/0167-4838(86)90200-1
M3 - Article
C2 - 3509976
AN - SCOPUS:0022542379
VL - 873
SP - 143
EP - 146
JO - BBA - Protein Structure
JF - BBA - Protein Structure
SN - 1570-9639
IS - 1
ER -