6278
P.-P. Kung et al. / Bioorg. Med. Chem. Lett. 18 (2008) 6273–6278
bound to copper on Yttrium-silicate scintillant beads. Test compounds which
bind to HSP-90 competed with tritiated propyl-Geldanamycin (3H-pGA) at the
ATP-binding site on HSP-90. For Ki determinations, % inhibition values are
plotted vs. log inhibitor concentration and fit to four parameter logistic
equation. The IC50 is converted to competitive Ki using Cheng–Prusoff equation,
46 gave the desired products (compounds 20, 21, and 24–29)
shown in both Tables 2 and 3 in 50–80% yield.
In summary, a series of potent Hsp90 inhibitors was discovered
by both focused library synthesis and structure-based design. The
two lead compounds (31 and 33) from this series displayed equal
or better potency compared with 17-DMAG in effecting the client
proteins’ degradation and cell proliferation in both A2058 and
MDA-MB231 cell lines.
where Ki is the inhibition constant,
L is the total concentration of
pGA = 200 nM, and Kd is the dissociation constant for pGA = 240 nM.
6. (a) Basso, A. D.; Solit, D. B.; Chiosis, G.; Giri, B.; Tsichlis, P.; Rosen, N. J. Biol.
Chem. 2002, 277, 39858; (b) Akt lum assay: non-small cell lung carcinoma cell
line H1299 was cultured in DMEM + 10%FBS, 10,000 cells/well were cultured in
96-well plate. Compounds were added to each well starting at 10 lM with
threefold serial dilution of 11 points of various concentration. Twenty-four
hours post adding compounds, cell lysates were prepared and subjected to
Luminex 100 system using the Beadlyte Akt/PKB kit—Upstate #46-605.
7. Grenert, J. P.; Sullivan, W. P.; Fadden, P.; Haysead, T. A.; Clark, J.; Mimnaugh, E.;
Krutzsch, H.; Ochel, H.-J.; Schulte, T. W.; Sausville, E.; Neckers, L. M.; Toft, D. O.
J. Biol. Chem. 1997, 272, 23843.
8. Ghiosis, G.; Timaul, M. N.; Lucas, B.; Munster, P. N.; Zheng, F. F.; Sepp-
Lorenzino, L.; Rosen, N. Chem. Biol. 2001, 8, 289.
9. Yang, Z.-Q.; Geng, X.; Solit, D.; Pratilas, C. A.; Rosen, N.; Danishefsky, S. J. J. Am.
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Acknowledgments
We thank the Pfizer La Jolla analytical group for chiral separa-
tion of racemic compounds. We also thank Drs. Peter Wells and
Rob Kania for helpful discussions, Dr. Yinsheng Zhang for preparing
the tritium-labeled 17-PGA, and Dr. Ketan Gajiwala for discussion
of co-crystal structures and graphical support.
10. (a) Dymock, B. W.; Barril, X.; Brough, P. A.; Cansfield, J. E.; Massey, A.;
McDonald, E.; Hubbard, R. E.; Surgenor, A.; Roughley, S. D.; Webb, P.;
Workman, P.; Wright, L.; Drysdale, M. J. J. Med. Chem. 2005, 48, 4212; (b)
Shen, G.; Blagg, B. S. J. Org. Lett. 2005, 7, 2157; (c) Brough, P. A.; Aherne, W.;
Barril, X.; Borgognoni, J.; Boxall, K.; Cansfield, K.-M.; Cheung, J.; Collins, I.;
Davies, N. G. M.; Drysdale, M. J.; Dymock, B.; Eccles, S. A.; Finch, H.; Fink, A.;
Hayes, A.; Howes, R.; Hubbard, R. E.; James, K.; Jordan, A. M.; Lockie, A.;
Martins, V.; Massey, A.; Mattews, T. P.; McDonald, E.; Northfield, C. J.; Pearl, L.
H.; Prodromou, C.; Ray, S.; Raynaud, F. I.; Roughley, S. D.; Sharp, S. Y.; Surgenor,
A.; Walmsley, D. L.; Webb, P.; Wood, M.; Workman, P.; Wright, L. J. Med. Chem.
2008, 51, 196; (d) Gopalsamy, A.; Shi, M.; Goals, J.; Vogan, E.; Jacob, J.; Johnson,
M.; Lee, F.; Nilakantan, R.; Petersen, R.; Svenson, K.; Chopra, R.; Tam, M. S.;
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Supplementary data
Supplementary data associated with this article can be found, in
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a SPA
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length or N-terminal HSP-90 that contains a 6-His tag on its C-terminus were