Petros A M, Neri P, Fesik S W
Pharmaceutical Discovery Division, Abbott Laboratories, Abbott Park, IL 60064.
J Biomol NMR. 1992 Jan;2(1):11-8. doi: 10.1007/BF02192797.
The solvent-exposed regions of (U-13C)ascomycin when bound to its putative target protein, FKBP, have been identified based on the different proton longitudinal relaxation rates (R1 = 1/T1) measured in the absence and presence of the paramagnetic relaxation reagent, 4-hydroxy-2,2,6,6-tetramethyl-piperidinyl-1-oxy (HyTEMPO). The proton T1S of bound ascomycin were determined using a pulse sequence (T1-HMQC) which consists of a 180 degree proton pulse and a variable delay (tau) followed by a heteronuclear multiple quantum correlation (HMQC) experiment. The solvent-exposed regions of ascomycin determined by these experiments are compared to NOE data in which ascomycin/FKBP contacts were identified and to the X-ray structure of the FK-506/FKBP complex.
