FIG. 11.

Intrinsic fluorescence of Δ21 in the absence and presence of divalent metals. (A) Upper panel, tryptophan fluorescence emission spectra of 1 μM HCV Δ21 in the absence of metal and in buffer containing either 0.1 or 2 mM Mg²⁺. Near the bottom of the graph are the spectra of the buffer used in the measurements amended with 2 mM concentrations of both Mg²⁺ and Mn²⁺. Lower panel, tryptophan fluorescence of 1 μM HCV Δ21 in the presence of 0, 0.1, or 2 mM Mn²⁺. (B) Upper panel, tyrosine fluorescence emission spectra of 1 μM Δ21 in the absence of metal, or in buffer containing either 0.1 or 2 mM Mg²⁺. Near the bottom of the graph are the spectra of the buffers used in the measurements amended with 2 mM of both Mg²⁺ and Mn²⁺. Lower panel, tyrosine fluorescence of 1 μM Δ21 in the presence of 0, 0.1, or 2 mM Mn²⁺. (C) Upper panel, tryptophan fluorescence of 1 μM HCV Δ21 in the presence of 0, 0.1, or 2 mM Ni²⁺. Lower panel, tryptophan fluorescence of 1 μM Δ21 in the presence of 0, 0.1, or 2 mM Co²⁺.