FIG. 6.

Dual ¹H-¹⁵N HSQC spectra of VP9 in the absence (red) and presence (blue) of Zn-sulfate (a) and Cd-sulfate (b). Shown is a superimposition of the ¹H-¹⁵N HSQC spectra of the free form of VP9 in red and in the complex with zinc sulfate/cadmium sulfate in blue at a ratio of about 1:4 at pH 6.72 and 298 K. Forty-two perturbed peaks that either disappeared or underwent chemical shifts refer to Asn56, Tyr43, Glu31, Glu72, Arg19, Met44, Leu12, Gln74, Val45, Gly50, Gly57, Leu11, Leu47, Lys35, Leu55, Glu21, Gly14, Thr6, Ile59, Ser36, Val13, Arg63, Asp40, Asp15, Met76, Thr52, Leu48, Cys46, Val78, Ala2, Thr80, Thr81, Ile77, Phe4, Asp7, Ala32, Phe10, Asp9, Leu64, Gln5, Glu61, and Leu62. Of 42 perturbed peaks, Asp9, Phe10, Glu31, Val45, Cys46, Leu47, and Leu48 were perturbed the most due to close locations to the metal binding sites.