FIG 5.

STD NMR spectroscopy of ChPyV VP1 and a putative Neu5Ac-negative ChPyV VP1 mutant. (A) Superposition of NJPyV VP1-3′SL (pink) and native ChPyV VP1 (gold) structures in cartoon representation. NJPyV VP1 side chains responsible for binding of 3′SL and respective ChPy VP1 residues are shown as sticks, with oxygen and nitrogen atoms colored in red and blue, respectively. (B) 1H NMR reference spectrum of 27 μM NJPyV VP1 with a mix of 1 mM 6′SL and 1 mM 3′SL. (C) STD NMR difference spectrum of the same sample as shown in panel B. (D) STD NMR difference spectrum of 50 μM ChPyV VP1 with the 1 mM 6′SL–1 mM 3′SL mix. (E) STD NMR difference spectrum of 50 μM ChPyV VP1 V78F with the 1 mM 6′SL–1 mM 3′SL mix.