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

Abstract

A novel C₃-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 ¹H-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 ¹H-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 × 10³ 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.