| X-RAY DIFFRACTION |
8.00 |
277 |
THE TERNARY COMPLEX OF DHFR
WITH NADPH AND SRI-9439 WAS FORMED BY MIXING HUMAN DHFR
(20 MG/ML IN 25 MM KPO4 (PH 7.0), 0.1 MM EDTA, AND 3 MM
NAN3) WITH 60 MM NADPH, FOLLOWED 15 MINUTES LATER BY 60 MM
OF INHIBITOR IN DMSO (FINAL CONCENTRATIONS OF 2 MM NADPH
AND 2 MM INHIBITOR). THIS COMPLEX SOLUTION WAS MIXED WITH
AN EQUAL VOLUME OF PRECIPITANT CONTAINING 24-33% PEG 4000,
0.2 M LI2SO4, 0.1 M TRIS CL (PH 7.9-8.4), AND EQUILIBRATED
WITH THE PRECIPITANT BY HANGING DROP VAPOR DIFFUSION AT
277 K. THE CRYSTAL GREW IN ABOUT 3 WEEKS. THE CRYSTAL WAS
FLASH-COOLED DIRECTLY IN LIQUID NITROGEN AFTER HARVESTING
INTO MOTHER LIQUOR CONTAINING 10% GLYCEROL., pH 8.00, VAPOR DIFFUSION, HANGING DROP |
