Ah. Baugher et al., LOCATION OF FLUOROTRYPTOPHAN SEQUESTERED IN AN AMPHIPHILIC NANOPARTICLE BY ROTATIONAL-ECHO DOUBLE-RESONANCE NMR, Biophysical journal, 75(5), 1998, pp. 2574-2576
Rotational-echo double-resonance (REDOR) C-13 NMR spectra (with F-19 d
ephasing) have been obtained of 6-fluorotryptophan complexed by a poly
meric amphiphilic nanosphere consisting of a polystyrene core covalent
ly attached to a poly(acrylic acid)-polyacrylamide shell. The REDOR sp
ectra show that aromatic carbons from the polystyrene core and oxygena
ted carbons in the poly(acrylic acid)-polyacrylamide shell are both pr
oximate to the F-19 of 6-fluorotryptophan. Molecular modeling restrain
ed by distances inferred from the REDOR spectra suggests that all of t
he 6-fluorotryptophans are in the shell but within 10 Angstrom of the
core-shell interface.