Figure 3
From: Global Implications of Local Unfolding Phenomena, Probed by Cysteine Reactivity in Human Frataxin
Probes used to evaluate cysteine accessibility. Absorption spectrum and chemical structure of (A) DTNB and \({{\rm{TNB}}}^{=}\) (50 µM), and (B) DTDPy and TPy− (50 µM). TNB= and \({{\rm{TPy}}}^{-}\) were generated by the addition of excess BME to 25 µM DTNB and DTDPy, respectively. FXN (30 μM) absorption spectrum (gray) is included to show protein absorption contribution to the measured signal. Vertical lines mark the wavelengths used to follow chemical modification reactions: 425 nm for DTNB and 324 nm for DTDPy. Ellman’s reagent or DTNB: 5,5′-dithiobis-2-nitrobenzoic acid and DTDPy: 4,4′-dithiodipyridine.
