Spontaneous self-assembly of nanospheres from trigonal conjugate of glutathione in water

A novel C-3-symmetric peptide conjugate bearing three glutathione units (trigonal-glutathione, TG) was synthesized and its self-assembling behavior in water was studied by dynamic light scattering measurement, electron microscopy, and H-1-NMR spectroscopy. In water, TG showed spontaneous self-assembly into nanospheres with the size of 100-250 nm. The size of TG assemblies is minimally affected by the concentration and pH. Concentration dependence of H-1-NMR chemical shifts in D2O revealed that TG is self-assembled by interactions between glutathione units (hydrogen bonding, electrostatic interactions) with an apparent association constant of K-a 6.36 x 10(3) M-1. Concentration dependence of light scattering intensity and guest-binding ability indicated that the nanospheres underwent structural changes from hollow to filled spheres depending on the concentration.