Figure 2
Fluorescence spectra of 8-[Ï•-575]-cAMP bound to PKA R subunits. 150 nM 8-[Ï•-575]-cAMP was incubated with or without fourfold molar excess of PKA R subunits as indicated in the figure. The excitation spectra (a) were detected at Em 617 nm and Ex 610 nm-430 nm; the emission spectra (b) were detected at Ex 575 nm and Em 680 nm-580 nm. The experiments were repeated four times with similar results.