Research Article

Interaction of Human Dopa Decarboxylase with L-Dopa: Spectroscopic and Kinetic Studies as a Function of pH

Figure 2

pH dependence of the internal aldimine emission fluorescence of hDDC. Emission fluorescence spectra of 10 μM hDDC in 50 mM Bis-Tris-propane at pH 6.0, 6.4, 6.8, 7.1, 7.4, 7.8, 8.2, and 8.5 upon excitation at 420 nm (a) and 335 nm (b). The inset of (a) shows the pH dependence of the emission intensity at 504 nm (•), while that of (b) shows the pH dependence of the emission intensity at 504 nm (∘) and 384 nm (•). The solid lines represent the theoretical curves according to (2) and (3).
161456.fig.002a
(a)
161456.fig.002b
(b)