1H NMR spectra of the encapsulation of ubiquitin within coordination spheres.

(a) Ubiquitin ligand 2a. (b) Ligand 1a. (c) Ubiquitin-containing sphere 3a after treating ubiquitin ligand 2a with ligand 1a (30 equiv) and Pd(NO3)2 (17 equiv) in D2O/CD3CN (1:1, 0.5 ml) at 45 °C for 3 h. Downfield shifts of the signals of the pyridine rings (Ha, Hb) confirm the formation of Pd-pyridine bonds in coordination sphere 3a, and the simple spectrum indicates the quantitative self-assembly of ubiquitin-containing sphere 3a. All spectra recorded at 500 MHz, inD2O:CD3CN=1:1, at 300 K.http://www.nature.com/ncomms/journal/v3/n10/fig_tab/ncomms2093_F2.html