Skip to main content
. Author manuscript; available in PMC: 2011 Dec 1.
Published in final edited form as: Biochemistry. 2006 Oct 3;45(39):12144–12155. doi: 10.1021/bi061005x

FIGURE 3.

FIGURE 3

Spectral changes (A–C) and difference spectra (D) observed with SCO 1441, SCO 2687, and SCO 6655 in the presence of GTP. Each of the assay mixtures contained 0.1 M Tris-HCl (pH 8.0), 5 mM MgCl2, 0.5 mM DTT, and 0.1 mM GTP in a total volume of 1 mL at 25 °C. The contents of the cuvettes were blanked in the absence of GTP. Spectra were acquired at various times after addition of GTP. The protein concentrations were (A) 7.5 µM SCO 1441, (B) 5.3 µM SCO 2687, and (C) 2.5 µM SCO 6655. The insets show that in each case the rate of the reaction is linear with the concentration of the protein. The difference spectra shown in (D) for SCO 1441 (−), SCO 2687 (•••), and SCO 6655 (---) were obtained by subtracting the spectrum of GTP acquired in the absence of protein from the final spectra that were obtained with each protein. The arrows denote increases and decreases in spectral features.